On installing on Bullseye, I usually install postfix, then configure it with "dpkg-reconfigure postfix".
I use postfix here only for logwatch and other system emails, so the setup isn't concerned with the Internet at large. The default list of systems to accept mail for doesn't look right to me: grissom.localdomain, grissom.localdomain, localhost.localdomain, , localhost * Why is the fully qualified host name in there twice, but not the hostname alone ("grissom")? (localdomain is my local TLD on a private network.) * What with the two commas toward the end? Shouldn't that be grissom.localdomain, grissom, localhost.localdomain, localhost -- Does anybody read signatures any more? https://charlescurley.com https://charlescurley.com/blog/