Rated 4 out of 5 stars
Good, but omits this Gmail-recommended setting:
1. In the 'Tools' menu, open Options.
2. On the 'Advanced' tab, open the General section.
3. Click the Config Editor button.
4. Type 'mail.server.default.fetch_by_chunks'
5. Double-click on the mail.server.default.fetch_by_chunks entry to set its value to false.
6. Close the 'about:config' window and then close 'Options' by clicking OK.
This prevents a problem with attachments being truncated.