Exchange 2003 Activesync HTTP 500 Error

Further to my Exchange 2003 / Activesync Troubleshooting Guide which can be found here, I was working remotely on a Windows 2003 Server with Exchange 2003 SP2 installed over the weekend having been asked to try and make Activesync work as they had read through my guide and not managed to get everything working properly.

Initially the server needed to have it’s DNS configuration fixed so that the server could talk to the Internet and allow me access, so once their IT department had resolved that issue I was given credentials and started to look at the problems on the server.

Checking the settings against my article, everything appeared to be set properly, but the test on the test site was throwing HTTP 500 errors (my least favourite!), so I followed Method 2 of KB883380 (remove and re-create the Exchange IIS Virtual Directories) and once they had been recreated and the IIS settings re-checked, I re-ran the test on the test site and still received the HTTP 500 error.  At that point I was debating a call to Microsoft, but started to check the Event logs on the server and saw various DNS related errors which were of some concern.

Outlook 2007 was also installed on the Exchange 2003 server, so I wasn’t convinced that I had a simple fix on my hands.

I ran the Exchange 2003 Best Practises Analyzer tool and that reported that Exchange could not be contacted, which suggested a DNS issue.  In the DNS logs there was an Event ID 800 error:

The zone <zone> is configured to accept updates but the A record for the primary server in the zone’s SOA record is not available on this DNS server. This may indicate a configuration problem. If the address of the primary server for the zone cannot be resolved DNS clients will be unable to locate a server to accept updates for this zone. This will cause DNS clients to be unable to perform DNS updates.

The suggested fix for this was to run dcdiag /fix followed by netdiag /fix and then to restart the Netlogon Service.  I did this but nothing changed.

Running the netdiag /fix threw up the following error:

DNS Error code: DNS_ERROR_RCODE_SERVER_FAILURE [FATAL] Failed to fix: DC DNS entry xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx._msdcs.internaldomainname.local. re-registeration on DNS server ‘Server IP Address’ failed.

I checked the DNS zones and saw that both the _msdcs.internaldomain.local zone and internaldomain.local zones were not showing all that they should have been so I deleted both zones and recreated them manually (referring to another Windows 2003 server for the relevant entries.  Once all that could be manually created was created, I re-ran dcdiag /fix and netdiag /fix and still received the error above.

I then tried searching for a way to fix this problem but drew a blank.  Looking through the other event logs, I came across the following error in the System Log:

Event ID: 5788
Source: Netlogon
Description: Attempt to update Service Principal Name (SPN) of the computer object in Active Directory failed. The following error occurred: The attribute syntax specified to the directory service is invalid.

Searching for this error landed me here and upon checking the Computer Name / Domain Name,  I saw that the computer name was simply computername. not computername.internaldomain.local.  Never seen that one before.

Following the resolution in the MS article, I created a VB Script file and ran it on the server and rebooted.

Following the reboot, I re-ran the dcdiag /fix and netdiag /fix and the errors had gone.  In addition, some of the DNS records that I wasn’t able to create manually were magically back, so that seemed to have resolved the DNS issues – hurrah!

I then decided to re-test Activesync and happily received a complete pass on all tests – so now that Exchange could talk to itself, Activesync could actually work!

Running the Exchange Best Practices Analyzer again I was happy to see that Exchange could now talk to itself and the results showed a much happier server with only a few minor issues.

So – if you are seeing the dreaded HTTP 500 error and have gone through my Guide, followed KB883380 method 2 and still get the same error – it just might be a good idea to run the Exchange BPA and check your DNS settings are 100% happy.


SBS 2003 to SBS 2011 Migration – 50Gb of Public Folders to Migrate took a week to migrate!

Having nearly completed yet another SBS 2003 to SBS 2011 Migration after the longest week of my life so far, I was amazed at how slowly the Public Folder Replica Move actually took to push 50Gb of data between the two servers.

Starting the project on a Monday and having the SBS 2011 server built by Monday afternoon (built virtually using Microsoft’s Hyper-V Server on a new HP ProLiant ML350 G6), I started to move the Exchange Mailboxes and then the Public Folder Replicas to the SBS 2011 server.  The network was originally running on a 10/100 Switch but I upgraded it to a Gigabit Switch on the Tuesday morning so that I had the maximum speed available and both servers had Gigabit cards in them.

At the end of the Tuesday, there were still dozens of Public Folders listed in the Public Folder Instances list in the Exchange System Manager, so I checked the SMTP Virtual Server Settings to see if there were any settings configured that might slow the process down and discovered several settings that would restrict the flow of emails.  The initial setting that I noticed was the “Limit session size to (KB):” setting.  This was limited to 40Mb and as some of the emails in the Public Folders were in the region of 30-40Mb in size, the session size was going to severely impact the flow of mail so I changed it to 1024000 (about 1Gb).

The other setting that I changed was the “Connection Timeout” value on the General Tab.  This was set to timeout after 10 minutes, so I increased the timeout to 2 hours, so that this wouldn’t cause any delays either.

I wasn’t unduly concerned at this point about problems with inbound mail and spammers clogging up the system as I had already installed a SAN/UCC SSL certificate (minimum 5 Domain Names) bought from and had re-pointed port 25 to the SBS 2011 server.

So having made as many changes to the network and SMTP Virtual Server Settings (also restarting the Simple Mail Transport Service) I created a new Receive Connector on the SBS 2011 server to only receive mail from the IP Address of the SBS 2003 server and set the Maximum Message Size Limit to 50Mb and let the two servers talk to each other.

Sometime overnight on the Saturday after starting the migration, the whole 50Gb of Public Folders had migrated across to the SBS 2011 server and all the Public Folder Instances had disappeared!  A whole 5½ days later.

At one point during the PF Replication, I calculated that it was moving at about 500Mb per hour, so all in all, it was going to take in the region of 100 hours to move the entire database.

So – if you are planning a migration from SBS 2003 to SBS 2011 and you have a large Public Folder Database, don’t expect the migration to complete quickly.  Assuming the worst – a Public Folder Database with 75Gb of data in it, I would expect it to take about a week and a half just to push the data to the new server.

Happy migrating!

SBS 2003 Connect To The Internet Wizard Fails At Firewall Configuration

Today I was working on a problem where an SBS 2003 server was having issues re-running the Connect To The Internet Wizard whereby the Wizard started happily to re-configure the server but then failed at the Firewall configuration.  The server also had ISA Server 2004 installed.

The reason for re-running the wizard was because emails were not flowing properly out of the server and re-running the Internet Connection Wizard was a good place to start troubleshooting.  Because the Wizard was failing, it was a strong possibility that the Firewall / ISA server was causing the issue.

Having examined the ICWLOG.TXT file to see what might be causing the issue (from C:\Program Files\Microsoft Windows Small Business Server\Support) it showed the following errors:

Error 0x80070003 returned from call to Configuring IIS to listen only on the LAN().
Error 0x80070003 returned from call to CStingrayCommit::DoGeneralConfiguration().
Error 0x80070003 returned from call to Doing general configuration().
Error 0x80070003 returned from call to CStingrayCommit::CommitEx().

Doing some digging on the webs for an answer, I checked a few sites but drew a blank, then I found the following site ( and it pointed me to check the registry for the following key:

the ‘companywebpath’ key showed this value:


Opening up IIS Manager, I then checked the IIS Website Identifier Value for the CompanyWeb site (see example image below) :
and saw that it was showing a different value, in this case it was showing ‘448260875’.

Going back to the Registry key, I then changed the ‘companywebpath’ value to 448260875 to mirror the IIS Website Identifier and then closed Regedit.

Upon re-running the Connect To The Internet Wizard again, it completed happily and normal outbound mail-flow resumed.

I am sure that this isn’t the only reason for the wizard failing at the firewall stage, but it is one thing to rule out that isn’t exactly obvious.

Problems Installing KB891193 on SBS 2003

I was starting an SBS 2003 to SBS 2011 Migration for a customer today and it failed the SBS 2003 SP1 check! So – I downloaded the relevant components and installed the ones that had not been installed. All fine and dandy, apart from when I got to KB891193 where it failed with Fatal errors repeatedly.

Scouring the web for solutions was pretty fruitless – suggestions of removing the Fax Service (make sure you have SBS 2003 CD1 handy) and running the update as Domain Administrator (which I was) proved fruitless.

I finally decided to try and remove the Client Apps which refused to comply, so as a last resort I felt that it might benefit from a reinstallation of the Client Apps part of SBS 2003 installation (make sure you have SBS 2003 CD3 handy!)

After what seemed like an eternity where nothing was happening, the reinstallation completed, the server rebooted and then I tried KB891193 again and it instantly installed without a single complaint.

So – after 8 hours of wasted time – I can now continue with my SBS 2011 installation! Roll on the weekend.

KB883380 Fails To Regenerate IIS Virtual Directories on Exchange 2003 / SBS 2003

I was working on a server yesterday so that I could change the certificate name from to

After generating a new Certificate Signing Request and submitting it to the certificate authority (, I verified the certificate, downloaded it and installed it onto the server in the usual manner and that was when everything went wrong.

I could not browse to the Exchange virtual directory, nor the exchange-oma virtual directory (this was an SBS 2003 server) and Actvesync / RPC over HTTPS was broken too!

So, as this was SBS, I decided to re-run the Connect To The Internet Wizard and let SBS work its magic to reset everthing back to normal. The wizard failed the Firewall section of the Wizard and my virtual directories were vaguely working. Resetting the virtual directories back to the required settings from my Exchange 2003 / Activesync article, this seemed to break IIS further!

So, following method 2 of KB883380, I deleted the IIS virtual directories, ran the Cscript command (adsutil delete ds2mb) and then ran “net stop msexchangesa && net start msexchangesa && net start msexchangeis” to stop and restart the System Attendant and then start it and the Information store (which stops with the System Attendant) and waited for 1 minutes.

After waiting 15 minutes and seeing that the virtual directories had not magically reappeared, I rebooted the server as recommended in the KB article.

So the server woke up again from its reboot and yet still no virtual directories.

What to do?

I then decided to re-install Exchange 2003 Service Pack 2 on the server as this quite often fixes things that are a little broken with Exchange / IIS, so I downloaded the Service Pack and installed it.

Bingo! The virtual Directories were back!!

In addition, I decided to re-key the new certificate just in case that was causing me some issues, so generated a new Certificate Signing Request, re-keyed the certificate and re-installed in onto the server.

I then re-ran the Connect To The Internet Wizard one more time, modified the IIS settings as per my article and then tested Activesync and RPC over HTTPS which was working perfectly.

So, in summary, if your IIS virtual directories do not re-appear after following any method from KB883380 and you have waited for 15 minutes, rebooted the server all to no avail, simply download and re-install Exchange 2003 Service Pack 2 and you should be back up and working again in no time.

Exchange 2003 and Activesync Configuration and Troubleshooting

So, here is my guide to solving (most) Exchange 2003 and Activesync issues:


1. Make sure that you have Exchange Server 2003 Service Pack 2 Installed. Whilst Activesync will work with Exchange 2003 Service Pack 1, Service Pack 2 makes it a whole lot easier!

To check if you have it installed, open up Exchange System Manager (Start> Programs> Microsoft Exchange> System Manager). Then expand Servers, Right-Click your server and choose Properties. This will display whether you have SP2 installed or not.

If you do not have SP2 installed you can download it here –

2. Ensure that TCP Port 443 is open (and forwarded) on your firewall to your Exchange server. You don’t need to open up any other ports to get Activesync working, just TCP port 443. You can check this on your Exchange Server at and you should see ‘Success’ if the port is open and forwarded correctly. If it isn’t open and forwarded, check your router and make sure you have the settings configured correctly.

3. Please check the LAN Adapter Binding order to make sure the NIC that Exchange is bound to is at the top of the list (Start> Run> [type] ncpa.cpl [press enter]> Advanced> Advanced Settings> Connections).

4. Open up IIS Manager (Start> Programs> Administrative Tools> Internet Information Services (IIS) Manager), expand ‘Web Sites’ then ‘Default Web Site’ then right-click on the relevant Virtual Directory (see below) and choose properties, then click on the Directory Security Tab):

Exchange 2003 (Not part of Small Business Server):

Exchange Virtual Directory
• Authentication = Integrated & Basic
• Default Domain = NETBIOS domain name – e.g., yourcompany* (no more than 15 characters)
• Realm =
• IP Address Restrictions = Granted Access
• Secure Communications = Both Require SSL and Require 128-Bit Encryption NOT ticked (very important)

Microsoft-Server-Activesync Virtual Directory
• Authentication = Basic
• Default Domain = NETBIOS domain name – e.g., yourcompany* (no more than 15 characters)
• Realm = NETBIOS name
• IP Address Restrictions = Granted Access
• Secure Communications = Both Require SSL and Require 128-Bit Encryption IS ticked

Public Virtual Directory
• Authentication = Integrated & Basic
• Default Domain = NetBIOS domain name – e.g., yourcompany* (no more than 15 characters)
• Realm =
• IP Address Restrictions = Granted Access
• Secure Communications = Both Require SSL and Require 128-Bit Encryption IS ticked (very important)

Exchange 2003 (Part of Small Business Server):

Exchange Virtual Directory
• Authentication = Integrated & Basic
• Default Domain = NetBIOS domain name – e.g., yourcompany*
• Realm =
• IP Address Restrictions = Granted Access
• Secure Communications = Both Require SSL and Require 128-Bit Encryption IS ticked (very important)

Microsoft-Server-Activesync Virtual Directory
• Authentication = Basic
• Default Domain = NETBIOS domain name – e.g., yourcompany*
• Realm = NETBIOS name
• IP Address Restrictions = Granted Access
• Secure Communications = Both Require SSL and Require 128-Bit Encryption NOT ticked

Exchange-oma Virtual Directory
• Authentication = Integrated & Basic
• Default Domain = NETBIOS domain name – e.g., yourcompany*
• Realm = NETBIOS name
• IP Address Restrictions = Restricted to IP Address of Server
• Secure Communications = Both Require SSL and Require 128-Bit Encryption NOT ticked

OMA Virtual Directory
• Authentication = Basic
• Default Domain = NETBIOS domain name – e.g., yourcompany*
• Realm = NETBIOS name
• IP Address Restrictions = Granted Access
• Secure Communications = Both Require SSL and Require 128-Bit Encryption NOT ticked

Public Virtual Directory
• Authentication = Integrated & Basic
• Default Domain = NetBIOS domain name – e.g., yourcompany* (no more than 15 characters)
• Realm =
• IP Address Restrictions = Granted Access
• Secure Communications = Both Require SSL and Require 128-Bit Encryption IS ticked (very important)

The Domain / Realm parts can be left as “\” for the Domain and Blank (empty) for the Realm.  MS recommend it this way, but I have fixed some servers by adding the Domain / Realm as per the settings above.

* yourcompany can be determined by opening up a command prompt (Start> Run> [type] cmd [press enter]) and then typing ‘SET’ and pressing enter. The variable ‘USERDOMAIN’ is the info you should use for ‘yourcompany’. Most often – this is not required, but I have seen instances where simply adding this info has made Activesync work.

5. ASP.NET should be set to version 1.1 for all virtual directories listed above. If you cannot see the ASP.NET tab, you only have v 1.1 installed so do not worry. If any version other than 1.1 is selected, please change it to v 1.1.4322.

6. Make sure that you have HTTP Keep-Alives enabled. Right-Click on the Default Web Site and choose Properties. On the Web Site tab, in the Connections section, click the Enable HTTP Keep-Alives check box and click OK

7. Check that Ignore Client Certificates is selected under the IISADMPWD virtual directory / Directory Security Tab / Edit Secure Communications Button. This Virtual Directory may not exist if you have not setup the ability to reset passwords via Outlook Web Access (OWA). If it is not there – no worries.

Please make sure that IPV6 is NOT installed on your server as this is known to break Activesync. (Start> Run> [type] ncpa.cpl [press enter]) Right-click on your Local Area Network Connection and choose Properties. Look under ‘This Connection Uses The Following Items:’ for Internet Protocol (TCP/IP) v6 – if it exists – uninstall it and reboot.

8. Ensure that the IP for the Default Website is set to All Unassigned and using port 80 (open up IIS manager, Right-Click the Default Website and choose properties, then on the Advanced button).

If your default website is using any port other than port 80, it simply will not work, so if you have changed this to make something else work, either change it back to port 80 or stop trying to use Activesync! Also make sure that you are not using any Host Headers on the Default Website (or any other website that you happen to have running that uses the same Host Header name that you are using on your SSL certificate) because this can/will also break Activesync.

If you make any changes to IIS, you will need to reset IIS settings. Please click on Start, Run and type IISRESET then press enter.

SSL Certificate
Make sure that the name on the SSL certificate you have installed matches the Fully Qualified Domain Name (FQDN) that you are connecting to for ActiveSync – for example, To check, right-click on the Default Web Site in IIS, choose Properties, click on the Directory Security Tab and then on the View Certificate Button.

If it does not match, either re-issue the certificate if you created it yourself, or re-key the certificate from your SSL certificate provider.

If you have a Small Business Server and don’t want to buy a 3rd Party SSL certificate, just re-run the ‘Connect To The Internet Wizard’, (Start> Server Management> To-Do List> Connect to the Internet).

Click Next. If the Wizard detects a Router – click No to leave the configuration alone.

Make sure ‘Do not change connection type’ is selected and click Next.

Leave the Web Services Configuration Settings as they are and click Next.

Select ‘Create a new Web server certificate’ and enter a ‘Web server name’ e.g., and click Next.

Select ‘Do not change Internet e-mail configuration’ and click Next.

Click Finish to complete the Wizard

If you have Windows Mobile Phones, Activesync is much easier to get working with a purchased SSL certificate. If you have a self-created SSL certificate and use Windows Mobile Phones, you will have to install the SSL certificate onto each and every Windows Mobile Phone that you want to use with your Exchange 2003 server. If you only have a handful of devices, then it won’t take long to do, but if you have dozens, a £30 1-Year SSL certificate is probably a very good investment. You can purchase a cheap, trusted SSL certificate from that will work happily.

Windows Mobile Phone / iPhone Settings:

Email Address: Your Users Email Address
Server: Whatever name you have on your certificate e.g., (do not add /exchange or /oma or /anything)
Domain: Your internal Domain Name e.g., yourdomain (maximum 15 characters)
Username: Your Username e.g., User123
Password: The CORRECT password!
Description: Whatever you want to call the Account


If you have got SP2 installed, check on to see if everything is working properly by running the Exchange Activesync check. The site is an official Microsoft site specifically for testing Exchange installations and connectivity.

Please select ‘Specify Manual Server Settings’ (Exchange 2003 does not have native Autodiscover enabled so using the Autodiscover settings will fail).

3rd Party SSL Certificate:

Do NOT check the “Ignore Trust for SSL” check box

Self-Certified SSL Certificate:

Check the “Ignore Trust for SSL” checkbox.

If you are trying to make an iPhone work, then you can also download the free iPhone App ‘Activesync Tester’ and this should identify any problems with your configuration, or download the version for your PC from

Various Activesync Errors / Solutions:

REMEMBER – If you make any changes to IIS settings, please run IISRESET and re-visit and re-run the test.

Activesync Error 0x86000108:

Activesync is unsuccessful and you see the error 0x86000108 on your Windows Mobile Device:
Please read the following MS Article which checks that Authenticated Users has write permissions to the %TEMP% directory (usually c:\windows\temp) –

Application Event Log 3005 Errors:

A lot of 3005 errors can be resolved by changing the Default Website Timeout value from 120 (default) to something greater, such as 480 using IIS Manager.
For Small Business Server 2003 Users – please read this MS article –

Inconsistent Sync:

If you are getting inconsistent Synchronisation from your device to your Exchange 2003 server, please add the following registry key to the server:
ProactiveScanning REG_DWORD 1

HTTP 401 Error:

If you are getting an HTTP 401 error when testing on then you are probably entering an incorrect username or password, or you may have IP Address restrictions setup on your virtual directories (see IIS Settings above under prerequisites).

HTTP 403 Error:

Ensure that Forms Based Authentication is NOT turned on under Exchange Virtual Server under Exchange Protocols (Exchange System Manager, Servers, Protocols, HTTP, Exchange Virtual Server properties, Settings Tab). If it is – please read and create an exchange-oma virtual directory following the instructions in the KB article.

I have had Activesync work despite seeing “An HTTP 403 forbidden response was received. The response appears to have come from Unknown. Body is:

HTTP/1.1 403 Forbidden

” at the end of the test above. To resolve this (if you like things tidy), please open up Exchange System Manager, Global Settings, Mobile Services Properties, Device Security Button, Exceptions Button, then add your account to the exceptions list.

I have also seen the 403 error resolved by running:
eseutil /p
eseutil /d and
isinteg -s servername -fix -test alltests (at least twice)

Check to see if Activesync is enabled globally on your server –

Also check to see if it is enabled on a user by user basis –

HTTP 500 Error:

If you still cannot get Activesync to work or keep getting an HTTP 500 error, please follow Method 2 in Microsoft Knowledgebase Article KB883380 and this should resolve the issues. This essentially deletes the Exchange Virtual Directories from the IIS Metabase (which can be corrupted) and rebuilds them. When deleting the Exchange virtual Directories, please also delete the Exchange-OMA virtual directory if it exists. Rebuilding those virtual directories often clears up problems that all the other steps above do not resolve.

If, after following KB 883380, Activesync still does not work and it keeps coming up with HTTP 500 errors, please do the following:

• Disable Forms Based Authentication – Exchange HTTP Protocol (if enabled)
• Remove SSL settings from the Exchange IIS virtual directory
• Run iisreset
• Test Activesync without SSL selected – hopefully this should work or give the OK result
• If okay – right-click on the Exchange Virtual Directory and select all Tasks> Save Configuration to a file. Name the file Exchange and save to the desktop
• Run Regedit (and be extremely careful here as you can kill your server very easily) then right-click on My Computer and select Export. Name the file as ‘EntireRegistry’ and save the backup of the registry to the desktop
• In regedit – locate HKLM \ System \ CurrentControlSet \ Services \ MasSync \ Parameters and delete the ExchangeVDir key from the right-hand pane.
• Close Regedit
• Right-click on the default-website and select New> Virtual Directory fom File. Browse to the desktop and click on the Exchange.xml that you created above, then click on Read file, select Exchange from the ‘Select a configuration to import’ section and click on OK. Select ‘Create a new virtual Directory’ and name the directory ‘exchange-oma’ and click OK.
• Right-click on Exchange-OMA virtual directory you just created and click Browse – you should see OWA open up happily
• Open Regedit and add the ExchangeVDir key back that you recently deleted as a String Value and then change the value to read /exchange-oma
• Close regedit
• Enable SSL and require 128-Bit Encryption on the Exchange Virtual Directory to ensure it is secure once again
• Enable Forms Based Authentication (if you want to use it) on Exchange > Protocols> HTTP
• Make sure that Integrated Authentication is enabled on the Exchange Virtual Directory
• Check that the Exchweb virtual directory does not have SSL enabled
• Run iisreset
• Test Activesync – it should hopefully be working now!

If the above fails, please check you event logs for Event ID 9667 – Source MSExchangeIS. If this event exists, please have a read of MS KB820379

In a recent question on, I was advised that running the following command against the unmounted database solved an HTTP 500 error, so if you are still having issues, please try running the integrity check (from a command prompt):

Isinteg –s servername –fix –test alltests

Select the dismounted database and let the check run. If you see 0 errors and 0 fixes, then all is well. If not, please re-run the test until you do (as many times as it takes – two usually is ufficient).

If you are still reading this article and are still seeing HTTP 500 errors, then we need to check the settings on the EXCHWEB Virtual Directory in IIS Manager.

Exchweb Virtual Directory
• Authentication = Anonymous
• Secure Communications = Require SSL and Require 128-Bit Encryption NOT ticked

Exchweb \ Bin Directory
• Authentication = Basic
• Secure Communications = Require SSL and Require 128-Bit Encryption NOT ticked

Exchweb \ Bin \ Auth Directory
• Authentication = Anonymous
• Secure Communications = Require SSL and Require 128-Bit Encryption NOT ticked

Exchweb \ Bin \ Auth \ USA Directory
• Authentication = Basic
• Secure Communications = Require SSL and Require 128-Bit Encryption NOT ticked

REMEMBER – If you make any changes to IIS settings, please run IISRESET and re-visit and re-run the test.

Recently added HTTP 500 Error solution for a server I worked on.

Hopefully if you are now at the bottom of my article, your mobile phones should now be synchronising happily. If that is not the case, please review your IIS Settings carefully and start at the top of this article again.

RECENT UPDATE (10/01/12) – A piece of software called [url=””%5DHide Folders 2009[/url] has been found to install a service called “FSPRO Filter Service” and a dll called FSPFltd.sys (in c:\windows\system32\drivers).  This program breaks Activesync.  If you have Activesync part working / part not working, please check your server for this software and if it is there – disable the service, move / delete the .dll file and restart your server.  Once restarted, Activesync should return to normal functionality!

RECENT UPDATE (29/05/12) – Please make sure that the server does not have Microsoft Security Essentials installed as this will break Activesync.  If you find it is installed – please uninstall it.

Recent Update (10/07/13) – DO NOT INSTALL programs such as Disk Keeper on any server running Exchange as it too will break Activesync!

If you are still not working – then you will probably have to call Microsoft to get support from them as something else not covered by this article is causing your problems.

So, in summary, you have reviewed and checked the settings in IIS to ensure that Activesync will work on your Exchange 2003 server, you have made sure that you have Exchange 2003 Service Pack 2 installed and you have run a test to make sure that your server is responding happily and by now, your iPhones and Windows Mobile phones should be happily synchronising.

Having got this far – and hopefully fixing your problems – if you have found this article helpful, please vote for it at the top of the page : )

* * * Please rate this article below if you have found it helpful * * *

Problems sending emails to external domains

If you face problems sending out emails, but only to a handful of domains, please run through the following checks / tests and make sure your environment is setup properly:

  • Check your domain on (subscription required) or (free) and see if you have a Reverse DNS pointer setup.  If you do not have one setup – call your Internet Service Provider (ISP) and ask them to set one up to match the Fully Qualified Domain Name (FQDN) that your mail server responds as e.g., Also, your mailserver FQDN should also be setup with something like  Any FQDN ending in .local or .internal or anything that is not a valid Internet Domain Name is not correct and should be changed otherwise you may experience problems sending out emails to some domains.
  • Check that your IP address is not listed on any Blacklists on – If you appear on any blacklists, then you may have problems sending mail to some domains who check against blacklists (not everyone does, but a lot do).  Follow the links on the results page to the particular blacklist site to find out the reason why you are listed (you may have an infected computer sending out spam that you are not aware of) and then deal with the issue before requesting removal from those blacklists (if you don’t deal with the problem, such as an infected computer, you will get removed from the blacklist, but will only re-appear again as more spam is sent out).  Once you know what you are facing, you can resolve the problem.

If you are blacklisted – configure your firewall / router to block all traffic on TCP Port 25 Outbound from all IP addresses apart from your Mail Server.  This should reduce the possibility of an infection from getting you blacklisted further and will help prevent getting listed again once you have cleaned up your network.

  • Check your IP reputation on Senderbase  You will either be Good, Neutral or Poor.  If your reputation is Poor – then you may have problems sending out mail and are most likely appearing on a blacklist or two somewhere.  If you are Neutral, then you may have had a problem in the recent past and are still recovering your reputation.  If you have a Good reputation, you should have no problems sending out emails.
  • Check to see if you have an SPF (Sender Policy Framework) record setup on – If you do not have a record setup, visit, run through the various options carefully and then you should see your SPF record in the final box at the bottom of the screen. Once you have an SPF record, you have to publish this record in your Domains DNS records by adding a TXT record with the SPF record as the data e.g., Type=TXT Record=(output from An alternative site to the site that you can use is
  • Check to make sure that the advertised IP Address in DNS for your primary MX record is the same IP address that you are sending mail from. Ideally – they should be the same for optimal mail-flow although if you are using a 3rd party spam filtering service or have inbound mail on one IP Address and outbound mail on another, this is not going to be possible.

If you do send out mail from a different IP address to the advertised MX record IP Address, please check that the Reverse DNS entry for this IP Address is also configured properly and that it resolves correctly to the same IP address (I use to check this – but you will need a subscription!). As an example, if you send mail out via IP and the Reverse DNS entry setup on this IP address by your ISP is, should also resolve in DNS back to the same IP Address.

Having checked all of the above and made any corrections to your configuration, your mail should be flowing better. If it is not and your house is now in order, you are not listed on any blacklists and you still have problems sending out mail to one or more domains, then it may be that the external domain may be specifically blocking you, (Hotmail are quite good at doing this for no particularly good reason) you will need to contact them to try to resolve the issue.