Someone asked me the other day, “How could I go about using Security Groups, to control users’ send size limits?” He basically had a limit of 2mb for all users, and wanted to allow users in a specific Security Group to send up to 50mb messages. Here is a basic breakdown of the process I suggested: Firstly, you need to confirm that the global transport limit is raised to 50mb.
You can view and set these limits using get-transportconfig and set-transportconfig respectively:
Get-TransportConfig | select MaxSendSize
The next step would involve setting the send connector to allow 50mb messages. You can use get-sendconnector to get a list of all send connectors, and their respective limits.
Get-SendConnector | Select Name, MaxMessageSize
And then use set-sendconnector to set the MaxSendSize Set-SendConnector “Connector Name” –MaxSendSize 50mb Finally, you need to control the individual users’ send limits. If you have to control it via groups, you can use the following command to first enumerate the users in the group, and then pipe that to the set-mailbox command. Replace testsizegroup with the group you need to control the size limits for.
((get-group "testsizegroup").members) | foreach {set-mailbox -identity $_.Name -maxsendsize 52428800}
This will set the MaxSendSize for all users in that group to 50 mb. This command will have to be rerun every time to add users to the group, so it would be advisable to schedule this command to run hourly / daily etc.