What is the largest attachment for Outlook?
How can I send files larger than 25mb in Outlook?
If the file size is more than 25 MB, you will see “Oops, this email has over 25 MB of files attached. To send these files, please use SkyDrive” message. The best thing is that you can still send your huge file by uploading it SkyDrive. One can upload the file to SkyDrive without leaving Outlook.com.
What is the maximum size of attachment in Outlook 365?
Additionally, in OWA, each attachment can be no larger than 25 MB. So with a 100 MB maximum send size, using OWA you could attach and send up to three 25 MB files in a single message.