===== What? =====
Recipe for a simple setup with postfix and dovecot as IMAP server.

<code>
rhel8.2 in KVM guest,
dnf -y install dovecot postfix nmap-ncat

$ vi /etc/postfix/main.cf
### modify: home_mailbox = Maildir/
$ systemctl restart postfix

$ cat /etc/dovecot/dovecot.conf
protocols = imap
listen = *
dict {
  #quota = mysql:/etc/dovecot/dovecot-dict-sql.conf.ext
  #expire = sqlite:/etc/dovecot/dovecot-dict-sql.conf.ext
}
!include conf.d/*.conf
!include_try local.conf
auth_verbose=yes
auth_debug=yes
$ vi /etc/dovecot/conf.d/10-mail.conf
### modify: mail_location = maildir:~/Maildir
systemctl start dovecot


for i in 0 1 2; do
  useradd -m user$i
  echo user$i | passwd --stdin user$i
done

# nc 127.0.0.1 143
* OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE LITERAL+ STARTTLS AUTH=PLAIN] Dovecot ready.
1 login user1 user1
1 OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS THREAD=ORDEREDSUBJECT MULTIAPPEND URL-PARTIAL CATENATE UNSELECT CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS BINARY MOVE SNIPPET=FUZZY PREVIEW=FUZZY LITERAL+ NOTIFY SPECIAL-USE] Logged in
2 select inbox
* FLAGS (\Answered \Flagged \Deleted \Seen \Draft Old)
* OK [PERMANENTFLAGS (\Answered \Flagged \Deleted \Seen \Draft Old \*)] Flags permitted.
* 2 EXISTS
* 0 RECENT
* OK [UNSEEN 1] First unseen.
* OK [UIDVALIDITY 1686160064] UIDs valid
* OK [UIDNEXT 3] Predicted next UID
2 OK [READ-WRITE] Select completed (0.002 + 0.000 + 0.001 secs).

</code>