Below are some of the limits for Office 365 accounts - more detailed information can be found at Exchange Online Limits  

Starting Monday, February 5, 2018, both Office 365 and UI Healthcare email systems increased the maximum message send/receive limits to 150mb.  This change is being made to allow easier collaboration within the University of Iowa.   Please keep the following in mind:

  • Maximum total message send/receive size is 150mb. This includes both the message content and attachments.
  • Attaching a large file to an email message requires uploading that file to the email system. This can increase the time required to send the message.
  • Email attachments count against overall email storage quota.
  • While the UI email systems allow sending and receiving 150mb email messages (including attachments), other external email systems continue to have smaller limits. Some common receiving limits are:
    • Gmail – 50mb
    • Outlook.com – 50mb
    • Yahoo – 25mb
    • Peer universities – varies
  • Whenever possible, it is advised to use a file collaboration tool for large files. The University of Iowa supports Microsoft OneDrive for Business which allows for file sizes larger than 150mb.
LIMIT TYPE Outlook
(Windows)
Office365.com
(OWA)
Outlook
(Mac)
Message send/receive size limit (including attachments) -  Keep in mind that someone's mailbox on the Office 365 server will be prohibited from receiving messages if they exceed their maximum quota limit.   Note:  when you attach a file to a message, the file size of the attachment increases (it can increase as much as 30% in size when it is sent).   150 MB 150 MB 150 MB
Address List Limit 1000 1000 1000
Storage - User Mailbox, Shared Mailbox, Resource Mailbox 50 GB 50 GB 50 GB
Recipient Limit per message 500 500 500
       

Quota Alerts Across Office 365:

Warning: 49GB 

Prohibit Send: 49.5 GB 

Prohibit Send/Receive: 50GB

Article number: 
103894
Last updated: 
April 19, 2018