The maximum email size limit for our servers is 50MB. This is not the limit for one specific attachment, but instead for the entire message. What this means is that regardless of whether you attach a file that is 50MB or you attach two files that are 25MB each, in both examples the size of the email is 50MB.
Please keep in mind, however, that email was not really designed to send very large attachments. While our attachment limit is 50MB, many other emails providers have far lower limits. For example, Yahoo limits attachments to 10MB. Also, if you send very large files, when other users download those files, it can cause their email client to hang while it attempts to download such a large file.
If you need to email a very large file, it is recommended to upload the file to your account and email a link to the file instead.