In 2016, the quota includes all service information and deleted items, and in 2010 only the user information. You need to wait 2-3 hours or execute the Update-StoreMailboxState command.Īlso note that mailbox quotas are treated differently in Exchange Server 2013/2016 and Exchange Server 2010. 'Exchange Online customers who need to send legitimate bulk commercial email (for example, customer newsletters) should use third-party providers that specialize in these services.Changing the quota per mailbox in Exchange 2016 is not immediately applied. They have stated that Office 365 is not meant to be a bulk email service. NOTE: Microsoft has implemented Receiving and Sending Limits. Storage - User Mailbox, Shared Mailbox, Resource Mailbox

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). 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. The University of Iowa supports Microsoft OneDrive for Business which allows for file sizes larger than 150mb. Whenever possible, it is advised to use a file collaboration tool for large files.While the UI email systems allow sending and receiving 150mb email messages (including attachments), other external email systems continue to have smaller limits.Email attachments count against overall email storage quota.This can increase the time required to send the message. Attaching a large file to an email message requires uploading that file to the email system.This includes both the message content and attachments. Maximum total message send/receive size is 150mb.This change is being made to allow easier collaboration within the University of Iowa. Starting Monday, February 5, 2018, both Office 365 and UI Healthcare email systems increased the maximum message send/receive limits to 150mb.

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

Exchange 2016 attachment size limit