NMAP:

25/tcp   open     smtp
587/tcp  open     submission

LOGS:

WITH SUBMISSION:

Mar  5 22:34:09 srf postfix/smtpd[8163]: connect from xxx.t-dialin.net[79.xxx.xxx.xx]
Mar  5 22:34:09 srf postfix/smtpd[8163]: NOQUEUE: reject: CONNECT from xxx.t-dialin.net[79.xxx.xxx.xx]: 554 5.7.1 <xxx.t-dialin.net[79.xxx.xxx.xx]>: Client host rejected: Access denied; proto=SMTP

WITH PORT 25:

Mar  5 22:39:01 srf postfix/smtpd[12552]: connect from  xxx.t-dialin.net[79.xxx.xxx.xx]
Mar  5 22:39:01 srf postfix/smtpd[12552]: AA42C3322AD: client= xxx.t-dialin.net[79.xxx.xxx.xx], sasl_method=PLAIN, [email protected]
Mar  5 22:39:01 srf postfix/cleanup[12591]: AA42C3322AD: message-id=<[email protected]>
Mar  5 22:39:01 srf postfix/qmgr[30513]: AA42C3322AD: from=<[email protected]>, size=1133, nrcpt=1 (queue active)
Mar  5 22:39:01 srf postfix/smtpd[12552]: disconnect from xxx.t-dialin.net[79.xxx.xxx.xx]
Mar  5 22:39:03 srf postfix/smtp[12592]: AA42C3322AD: to=<[email protected]>, relay=gmail-smtp-in.l.google.com[74.125.77.27]:25, delay=1.6, delays=0.11/0.02/0.07/1.4, dsn=2.0.0, status=sent (250 2.0.0 OK 1299361143 p10si1877141eeh.48)
Mar  5 22:39:03 srf postfix/qmgr[30513]: AA42C3322AD: removed
Mar  5 22:39:09 srf postfix/smtpd[8163]: timeout after CONNECT from xxx.t-dialin.net[79.xxx.xxx.xx]
Mar  5 22:39:09 srf postfix/smtpd[8163]: disconnect from xxx.t-dialin.net[79.xxx.xxx.xx]

TELNET:

      telnet domain.com 25
      Trying 213.xx.xx.xx...
      Connected to domain.com.
      Escape character is '^]'.
      220 domain.com ESMTP Postfix (Debian/GNU)


      telnet domain.com 587
      Trying 213.239.209.150...
      Connected to domain.com.
      Escape character is '^]'.
      554 5.7.1 <xxx.t-dialin.net[79.xxx.xxx.xx]>: Client host rejected: Access denied

master.cf (submission extract)

    ==========================================================================
    smtp    inet    n       -       n       -       -       smtpd
    submission      inet    n       -       n       -       -       smtpd
    -o smtpd_etrn_restrictions=reject
    -o smtpd_enforce_tls=yes
    -o smtpd_sasl_auth_enable=yes
    -o smtpd_client_restrictions=permit_sasl_authenticated,reject
    -o smtp_generic_maps=
    -o sender_canonical_maps=