Wednesday 21 May 2008

Microsoft to withdraw per incident support for Hosted Exchange (you need a proper support contract!!)

If you're a provider of Hosted Exchange/HMC, should should read this:

If you've got an HMC platform then you need to have the appropriate Service Provider Support Contract in place from end-June. Microsoft are withdrawing the per-incident credit-card support for HMC, often used by smaller Hosting providers to gain support from Microsoft for inidents and issues.

We've got one and it's very very useful - not only have the global hosting support team undertaken a review of our platform so that they understand us better, we also get a named TAM (Technical Account Manager; Paul you are a hero!) with pro-active support and training from MS too.

BTW, Gavin's blog is a useful source of SaaS & Hosting news with a focus on the UK. Gavin works in the UK Hosting team for Microsoft (a useful contact for you all)

Tuesday 20 May 2008

Update Rollup 2 for Exchange Server 2007 SP1 Released

Microsoft have released another rollup fix for Exchange 2007 SP1 to follow on from rollup 1 a few months ago.

You can download it from

This update has all the fixes that were in Rollup 1 included so you can now just install rollup 2 and you will get all the latest updates.

A description of the fixes included in rollup 2 can be found at

Tuesday 6 May 2008

Now you can all get Xobni for your inbox

Well done to the team at Xobni - after 7 months of invite-only beta testing, it's now available for publicly for anyone to download.

You can get it here
Have a look at the video on their site if you still need convincing... it's good stuff.

Thursday 1 May 2008

Mail enabled Contacts in a Hosted Enviroment and the Offline Address Book.

Contacts in a Hosted Exchange environment can be tricky to implement succesfully, with 1) the way Exchange searches object attributes to create an Offline Address Book and 2) Active Directory not allowing 2 objects to have the same proxy address (which in all fairness is actually a great necessary check in the GUI to have – although this can be bypassed with LDAP manipulation! (ADSI too) – Note: having two objects with an identical proxyaddress will break delivery to that address and is considered attribute corruption of Active Directory).

So how does the Exchange 2003 System Attendant (using oabgen.dll) determine objects to be included for OAB generation? - It looks to see if the object has two attributes: a ‘proxyaddress’ and ‘mail’ attribute. It will further check to ensure the primary (SMTP in uppercase) ‘proxyaddress’ matches the mail attribute address.

So how does an Exchange Hoster get around 2 companies having the same contact of for example?

First let me explain the TargetAddress and ProxyAddress attributes on a mail enabled AD contact.

The TargetAddress is their actual email address, for example :
The ProxyAddress is what RUS (if you use it – HMC disables all but Enterprise RUS (enabled for System Attendant operation)) stamps on the objects email addresses tab. RUS can of course be told to bypass objects by unchecking ‘Automatically update email addresses based on recipient policy’. You will find the primary proxyaddress will be the address of the contact, matching the targetaddress, and depending on RUS and Recipient Policy configuration it could well be stamped with further proxyaddresses.

So, – how can two customers have this contact in an HMC/Hosted Exchange environment?

The short answer is they can, but it cannot show up in the OAL. This is due to the Offline Address Book generation specifying proxyaddress attributes I mentioned earlier, rather than also considering targetaddress attributes.

99% of hosters won’t have this problem – and contacts will be generated with a proxy address (something HMC supports by default). However when you run into this problem it does cause customer grief.

One way of bypassing it is to give a bogus proxyaddress, for instance ‘’, where HostedCompanyName is the name of the Hosted Exchange customer.

This does work, but introduces other issues when a user outside the Org performs a ‘Reply All’. Take a look.

Here’s the properties of the contact from the GAL:

Here’s the contact from the AD, I have pulled the info from ADSIEdit:

You can see the highlighted proxyaddress and targetaddress attributes clearly:

When you send a message outside of the Org, and include the contact, if anyone that is also outside the Org does a 'Reply All', they will only see the incorrect proxyaddress and not the correct SMTP address of the contact, which is the targetaddress:

This of course will result in an NDR

The fix? Remove the proxy attribute altogether, removing the contact from OAB generation, or have the primary proxy address match the target address (standard Exchange2003/2007 behaviour) – but something that will cause mail flow issues when you get a customer with the same contact.

Oliver Moazzezi

MVP - Exchange Server