Been trying to convert from Mac Mail to Thunderbird in the quest to get to more open source. Here are the issues:
- Thunderbird has this automatic identification of mail servers, but it doesn’t go to SSL encryption automatically, so you need to go to Tools/Account settings and change to SSL/TLS and this will switch the ports. YOu have to do the same for the SMTP server and this will also switch ports.
- Signatures are buried in the product, you have to go to Tools/Account Setting and click on each to add the signature, but you can use general HTML to make a really cool one.
- If you install enigmail, then you can use GPGTools for pgp encryption and signing.