Comment 99 for bug 1876286

I'm able to confirm the focal-proposed updates/3.6.13-2ubuntu1.2 worked for pop connections to pop.verizon.net on port 995. I started with a fresh install of Ubuntu 20.04 and applied all updates except proposed. In order to make GnuTLS 3.6 use an older version of TLS I created the file /etc/gnutls/config with the following contents:
[overrides]
default-priority-string = NORMAL:-VERS-TLS1.3

As expected gnutls-cli and evolution returned the error. After installing the proposed versions of libgnutls30 and gnutls-bin I was able to connect to the server with both programs.

I also used gnutls-cli to connect to imap.aol.com port 993 as a second check to make sure the new code supports zero length tickets. I also tried port 443 on www.yahoo.com, www.google.com, www.microsoft.com, and www.cnn.com as regression tests. All tests connected to the server and started simple client mode. No errors were displayed. Wireshark confirmed that the connections were using TLS 1.2 and that the aol and verizon servers returned zero length tickets.