Email message size

posted Nov 13, 2011, 8:17 PM by Rita Girardi   [ updated Dec 19, 2011, 1:00 PM ]
What: Maximum message size on accounts will be fixed at 25 MB  
When: February 4, 2012
Why: In preparation for the Ann Arbor and Dearborn campus migration to Google mail
Who: All email accounts on all campuses (including Flint)
Action: None. Awareness only.


Before the migration phases begin, maximum message size (including attachments) for mail sent from accounts will be fixed at 25 MB. This change prepares us for next year’s migration to Google email, which has a message limit size of 25 MB.

This change will be made on the outbound mail relays and will not require any modifications to existing email programs or servers. Messages not routed through the central mail gateway will not be affected. The new size limit should not alter current email practices for most users. However, for those using the campus ITS IMAP and Exchange service this is a reduction from the current maximum message size of 100 MB.

For file transfers larger than 25 MB, consider using the Mfile service to securely host and share files. Information and support for Mfile is available on the ITS Help pages. For support or assistance using Mfile, please contact the Service Center at or call 734-764-HELP (764-4357).

Note: Messages larger than 25 MB will be maintained in their current email systems after the move to Google takes place. They will not be deleted or migrated. However, at the end of the project, the university’s legacy email systems (e.g. ITS IMAP and ITS Exchange) will be retired and any email residing on those systems will no longer be accessible. Therefore, users should save any large messages or file attachments they want to keep to a secure location before or soon after their email accounts are transferred to the Google platform.