mail.plus.net certificate not trusted

[#1]

Apple's Mail client has started reporting the certificate for mail.plus.net as untrusted, see it was renewed a couple of days ago and there was a similar thread on the same issue back in 2021.

[#2]

see this is being covered by https://community.plus.net/t5/Email/Mail-can-t-verify-the-identity-of-the-server-imap-plus-net-quot/...

[#3]

Moderator's note:
Topic locked in favour of https://community.plus.net/t5/Email/Mail-can-t-verify-the-identity-of-the-server-imap-plus-net-quot/...