Debian 8.5 - Postfix - Dovecot: setup completed - mails don't reach destination mail address
I have deployed a fresh Debian 8.5 image from DO, and both Postfix (2.11.3) and Dovecot (2.2.13) according to these tutorials:
--- How To Set Up a Postfix E-Mail Server with Dovecot
--- How To Set Up a Postfix Email Server with Dovecot: Dynamic Maildirs and LMTP
Then, sending test mails from the command line with "mail firstname.lastname@example.org", they don't reach that account, and there are no errors in [/var/log/] mail.log, mail.err, mail.warn, syslog.
I'm lost :(
Need your quick help in order to be able to get my mail server running...!
Thanks in advance,