What is the size limit for email attachments?

The maximum size for an email is 10 MB. If this size is exceeded, the email is refused as undeliverable.

Most attachments need to be considerably smaller than 10 MB. The average file grows in size by up to 50% when it is converted to an email attachment. In practice, the largest file you can send is about 6-7 MB.

Your connection speed also controls the largest file size you can send. The mail server has a five minute limit for sending an individual email. The average dial-up connection can send a file of about 2 MB in that five minute limit.

If you regularly send extremely large files, you probably should be using another means to transfer the files. Video, large collections of digital images, and other large files usually work better — and faster — with services devoted to those purposes.