What is the size limit on emails I can send?

The email size limit is 50MB, if you try to send an email larger than that the email will fail to deliver.

If you need to send someone a file large than 50MB in size, you should use a file sharing service (such as Google Drive, Microsoft Onedrive, or Dropbox) rather than sending it in your email.

You would attach a downloadable link to this file that you had uploaded to your selected file sharing service in the email you do send.  Your recipient would then be able to click on the link in the sent email and download the file that is larger than 50MB in size.