Implement Provider Auto-Configuration for Clients (PACC)

Checklist

• I have used the search function to see if someone else has already submitted the same bug report.
• I will describe the problem with as much detail as possible.

App

Thunderbird for Android

App version

20.1

Where did you get the app from?

F-Droid

Android version

15

Device model

No response

Steps to reproduce

Try to add an account on a server using draft-ietf-mailmaint-pacc

This is a new standard that has a nicer format than autoconfig and is also much more secure. The published digest in the DNS record protects against potential attacks on the web server. It also doesn't support MX discovery like auroconfig that is vulnerable to MITM attacks.

Evolution implemented support in https://gitlab.gnome.org/GNOME/evolution/-/merge_requests/219

I can implement that feature and submit a pull request if you are willing to accept it.

Expected behavior

Thunderbird should support draft-ietf-mailmaint-pacc

Actual behavior

Thunderbird does not support draft-ietf-mailmaint-pacc

Logs

No response

Start by reviewing Thunderbird for Android's existing autoconfig account setup and the draft-ietf-mailmaint-pacc standard; the issue does not name specific files or tests. Compare the Evolution merge request linked in the issue, then verify that adding an account through PACC works and that its DNS digest and security requirements are respected.