Running ausearch -m avc , i get a list of logs similar to the following:
time->Sun Mar 22 19:12:54 2020
type=AVC msg=audit(1584900774.568:350): avc: denied { name_bind } for pid=1595
comm="dovecot" src=587 scontext=system_u:system_r:dovecot_t:s0
tcontext=system_u:object_r:smtp_port_t:s0 tclass=tcp_socket permissive=0
----
By "followed the Fedora 31 documentation" do you mean "dnf install
dovecot", .. yes exactly. I think I located the configuration file that is
responsible for dovecot to try use port 587 (and it comes out of the box, it's not
me)
/etc/dovecot/conf.d/10-master.conf
service submission-login {
inet_listener submission {
#port = 587
}
}
so I guess Mr.Spock is right: why Dovecot should work on this port if it is not supposed
to do so? The idea that SELinux is blocking it convinces me. Much more reading the note
contained in the page linked above
https://doc.dovecot.org/admin_manual/submission_server/
where it looks like the submission server is a fairly recent feature of Dovecot, that a
few people is aware of.
A little bit more work and I will manage to overcome the problem (hopefully before some
star date 20200).
Thank you guys for all the inputs, appreciated.