Microsoft Outlook enforces limitations on mass emailing. The current sending limits are as follows:
- 500 recipients per message: Exchange Online allows a maximum of 500 recipients across the To, Cc, and Bcc fields for a single email message sent through Office 365 (OWA or the Outlook desktop client).
- 10,000 recipients per 24 hours: There is a maximum of 10,000 recipients within a 24-hour period. This applies to the total number of recipients sent from the mailbox and is not limited to mass email campaigns.
Based upon these limits, it is recommended to:
- Spread communications out over multiple days: depending upon the number of communications that need to be sent, users can distribute their recipient lists across two to three days to help remain within the applicable sending limits.
- Work with University Marketing Communications (UMC): UMC offers support with Email Marketing leveraging institutional newsletters and campaigns. They may be able to assist in broader communications to our University audiences.
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