UW Email Frequently Asked Questions
How much email storage do I get?
Students, faculty, and staff whose mail resides on the Microsoft Office 365 servers receive 100 GB of storage space for email messages. For users needing additional storage Information Technology can enable archive mailbox for your email. This will increase storage by an additional 100 GB in the Microsoft cloud.
How many recipients can a UW email message be sent to?
Email is restricted to a maximum of 500 recipients. Addresses entered into the To, CC, and BCC fields all count towards this limit. Mailboxes can only send to a maximum of 10,000 recipients in a 24-hour period. Users can bypass both of these limits through the use of a mailing list.
In the second half of 2025 Microsoft will be implementing new bulk mail restrictions. Microsoft will set an external (non-campus emails) rate limit of 2000 recipients in rolling 24-hour period. If a user is sending bulk mail to off-campus users (such as a newsletter) from their personal UW address or a service account, they will be limited. It is important to note that this does not impact messages leaving mailman lists.
What is the maximum size of a UW email message?
The maximum size of a UW email message is 50 MB. Some email clients may have lower message size limits.
What are the email retention times?
· Users deleted items are retained for 30 days. After that time, they are automatically deleted.*
· Email records may be retained indefinitely in accordance with the records retention schedules set by the Wyoming State Records Committee.
What are the receiving Limits?
Mailboxes are restricted to receive a maximum of 3600 messages per hour. Individual senders are capped at 33% of the total limit. For example, if user a@uwyo.edu send user b@uwyo.edu 1201 messages in an hour only the first 1200 would be accepted and any over that would be rejected.
What other email limits exist?
Other default limits for Exchange Online can be found here.
* Some exceptions to mail deletion exist in specialized circumstances.