Microsoft 365 (M365) email accounts at CSU have specific limits on sending emails to maintain account security and prevent unauthorized mass messaging. These restrictions do not apply to CSU-specific distribution lists or mailing lists.
Applicable to: Fort Collins, Pueblo
Affiliation: Students, Faculty, Staff
Sending Limits
Message sending limits for Colorado State and CSU Pueblo Microsoft 365 (M365) email accounts:
- Maximum number of recipients in all emails sent in a 24-hour period: 2,000 recipients per 24-hours
- Maximum number of recipients per 24 hours with an exception: 10,000 recipients per 24-hours
- Maximum message size: 25 MB
- Maximum attachment size: 35 MB
- Maximum number of recipients in a single email: 500 recipients per email
Note: Sending emails to Exchange distribution lists are considered as being sent to a single recipient.
Details
- Limits prevent unauthorized mass emails in the event of account compromise, restricting potential impact and ensuring a suitable range for regular communications.
- Accounts that exceed the daily limit are blocked from further sending until reviewed and unblocked by the Division of IT.
- CSU defines a day as any rolling 24-hour period.
Exception process
Users needing to send more than 2,000 emails in 24 hours can request an exception by contacting help@colostate.edu. Users should also consider leveraging mailing lists to reach large groups without bypassing the standard sending limits.
Outcome
By following these guidelines, CSU users can understand the email sending parameters, prevent accidental account restrictions, and manage large email distributions efficiently.