Recently, I was involved in a discussion about how it might be possible to create MailTips on a per-domain basis. In Exchange, it's possible to create a remote domain for a specific address space, such as contoso.com, and configure different settings for that domain such as automatic forwards, automatic replies, out-of-office settings and so on. The specific question relating to MailTips and remote domains was essentially :

"Is it possible to configure MailTips on a per-domain basis?"

In this particular case, the desired outcome was to use MailTips to remind users within a particular Exchange organization that they were sending email to another user that was from one of a number of trusted partners, such as partners working for Contoso and therefore having an SMTP address ending with contoso.com. A quick look through the Understanding MailTips topic (http://technet.microsoft.com/en-us/library/dd297974.aspx) didn't reveal any information on setting MailTips on for a particular remote domain, although the MailTips Architecture section of the topic did discuss MailTips over organizational relationships. What if you don't have or don't want an organizational relationship?

Let's say, for example, that your Global Address List (GAL) has several mail-enabled contacts for a number of trusted partners working for Contoso and you want MailTips to be seen by your users when they are sending messages to these contacts. Additionally, you also have a number of mail-enabled contacts in the GAL representing users at a free email service provider such as Hotmail. You also want to ensure that your users are reminded they are sending to Hotmail when they are addressing these contacts. One way to achieve MailTips in this scenario is to configure custom MailTips. In order to filter the contacts in the GAL correctly, we can make use of the custom attributes that ship with Exchange Server 2010. For example, we could set CustomAttribute1 on all mail-enabled contacts for the company Contoso to a suitable string such as "Contoso". We can then identify these contacts and set a custom MailTip using the following command:

Get-MailContact | Where {$_.CustomAttribute1 -eq "Contoso"} | Set-MailContact -MailTip "This person works for Contoso"

This command returns all mail-enabled contacts whose CustomAttribute1 attribute is set to "Contoso", then proceeds to set the custom MailTip accordingly. The result is that when a user addresses this contact they receive the custom MailTip as you can see below:

To create a custom MailTip for contacts that use services such as Hotmail, we can run a command similar to this:

Get-MailContact | Where {$_.PrimarySmtpAddress -match "hotmail.com"} | Set-MailContact -MailTip "This person uses Hotmail.com"

Of course, there's an administrative overhead with this approach but it perhaps goes some way to addressing the need of custom MailTips for specific sets of contacts.

Per-Domain Mail Tips?

Microsoft Downloads Site : Office 365 and Exchange Updates