A friend noticed me that we also gen an alert when we try to send an email to an external recipient; it’s just that by default it doesn’t do that. This option needs to be enabled at the organization level.

With Get-OrganizationConfig | fl *mailtips* we can see the mailtips settings.

To activate mailtips for the external recipients we use the following command:

Set-OrganizationConfig -MailTipsExternalRecipientsTipsEnabled:$True

Now when I try to send an email to an external user I get the following warning in Outlook:

Same is happening when I try to send an email to a distribution list that contains an external recipient.

MailTipsLargeAudienceThreshold is refering to the number of members that a distribution list may contain to be considered Large Audience.

To better understand what MailTipsGroupMetricsEnabled is all about take a look here. MailTips uses Group Metrics to determine in a group is Large Audience or contains external recipients. Group Metrics runs once per day on the server that generates OAB and the only method to force it to run outside of his schedule is to restart the Exchange Service Host service. Be careful when you have Exchange 2007 together with Exchange 2010: if the OAB is generated on a Exchange 2007 server, Group Metrics will not be generated. Same is happening when OAB is distributed only via Public Folders.

The Group Metrics data are stored in a share folder named Group Metrics on the server that generates OAB, and are retrived by the CAS server through the Exchange File Distribution Service.

The last option we are mentioning is MailTipsMailboxSourcedTipsEnabled and is refering to object level MailTips. Object level means: mailbox, contact or group. To do this we use the parameter MailTip in the following cmdlets:

Set-Mailbox
Set-MailContact
Set-MailUser
Set-DistributionGroup
Set-DynamicDistributionGroup
Set-MailPublicFolder

In the following example I have set a description for a group, description that will be shown every time somebody tries to send an email to the group.

There’s a 250 characters limit for these MailTips and translations can be set using -MailTipTranslations parameter.

That’s all for today!

HTH

I will show you how Mail Tips work by using a very simple scenario. Sending an email to an user that has set Out of office auto reply. before I will have a chance to send the email, I am warned that the destination user has an Automatic reply set – so it’s very likely that my message will not be read (or not very soon).

Other examples where Mail Tips are useful are: sending an email to a user with a full mailbox; emails with attachments that do not comply with the organization rules, or emails sent to a restricted recipient (delivery restrictions are set).

Mail Tips warns the user when the email is sent to a distribution group with more than 25 members (this is the default settings and can be changed), or when one tries to Reply-All BCC – reply all to a message where you were initially in the bcc field.

These MailTips can be customized at the organization level or even at the recipient level, but more about that in another post.