[Dovecot] Rejected mails

[sunhux G]

Even if I'm inside the box itself & send emails to myself, it was not
received too (despite that sending to external emails including gmail
was Ok) :

# mailx -s "tst to localhost" myunixid at localhost < /etc/hosts
# mailx -s "tst to myportaltech" myunixid at myportaltech.com < /etc/hosts
# mailx -s "tst to hostname" myunixid@`hostname` < /etc/hosts
# mailx -s "tst to local private IP" myunixid at private_IP_addr < /etc/hosts

# su - myunixid
$ mailq
/var/spool/mqueue is empty
                Total requests: 0