On our hosting, each email (including attachments) can be up to 20MB.
Remember that the recipient's provider has its own limit and the smaller limit applies. For example, Gmail accepts about 25MB, Outlook.com about 20MB and many company Exchange servers only 10MB.
Attachments are also encoded when sent, which makes them roughly a third bigger. In practice, keep total attachments under about 14MB.
Sending larger files
- Upload the file to a sharing service (OneDrive, Google Drive, Dropbox, WeTransfer) and email a link
- Compress files into a .zip
- Reduce image sizes before attaching
