required documentation improvements on intransparent STARTTLS behavior due to sslcertck default, and others
revisit https://bugs.launchpad.net/ubuntu/+source/fetchmail/+bug/1934155/comments/3 and possibly other comments and improve documentation
revisit https://bugs.launchpad.net/ubuntu/+source/fetchmail/+bug/1934155/comments/3 and possibly other comments and improve documentation