'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. 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 youВ attachВ a fileВ 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 150mbВ 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. This encoding increases the size of the email by 33.

In that change the size from 10000 to 30000 (depending on your attachment size) In the search ribbon change the selection to 'All Mail' - 3rd button from top left in the ribbon or 'All Items' to get the results from all the Outlook items.

It must be encoded to email infrastructure friendly format. Click on attachments -> greater than 10 MB This will open up a search bar. Also, the email you send canвЂ™t be sent it the format you send it in. Starting Monday, February 5, 2018, both Office 365 and UI Healthcare email systems increased the maximum message send/receiveВ limits to 150mb. Outlook allows only 20MBs while other providers like Google and Yahoo mail limit the size of attachments to 25MBs. Below are some of the limits for Office 365В accounts - more detailed information can be found at Exchange Online Limits

Outlook 2016 attachment size limit