I have setup postfix with dovecot, dkim, spf, rDNS etc. on centOS 5
Everything works sending/receiving emails from outlook android device etc.
The only problem i have is that gmail and maybe other providers will block me because the client appears as unknown example from log when i send email trough outlook.
Sep 17 12:20:59 localhost postfix/smtpd[19080]: connect from unknown[xxx.xxx.xxx.xxx]
Sep 17 12:21:01 localhost postfix/smtpd[19080]: E320D2437AF: client=unknown[xxx.xxx.xxx.xxx], sasl_method=LOGIN, sasl_username=admin
Sep 17 12:21:02 localhost postfix/cleanup[19086]: E320D2437AF: message-id=<20130917082101.E320D2437AF@mail.xxx.com>
Sep 17 12:21:02 localhost opendkim[18754]: E320D2437AF: DKIM-Signature field added (s=default, d=xxx.com)
Sep 17 12:21:02 localhost postfix/qmgr[18765]: E320D2437AF: from=<admin@xxx.com>, size=1045, nrcpt=1 (queue active)
Sep 17 12:21:02 localhost postfix/smtpd[19080]: disconnect from unknown[xxx.xxx.xxx.xxx]
I tried everything without any success
Best Answer
"Unknown" refers to dns name of a host. This means, that your server could not resolvr ip into dns. So it is not related to your problems with gmail and other providers. For example, when your server can resolve ip, then the message will be something like:
postfix/smtpd[17224]: connect from xxxxx.net.local.com[xxx.xxx.xxx.xxx]UPD.
How to understand, that you have problems with ip to domain name resolutions:
Get an "unknown" ip from log.
Type in the shell of your mail server the following command:
host xxx.xxx.xxx.xxxMost likely you'll get response like:Host xxx.xxx.xxx.xxx.in-addr.arpa. not found: 3(NXDOMAIN)To clarify finally if there's a problem in your dns server, do the following:
dig xxx.xxx.xxx.xxx.in-addr.arpaLook in "AUTHORITY SECTION", record right after "SOA". This should be the dns server that supports the subnet (ns1.dnssrvr.com for example).
host xxx.xxx.xxx.xxx ns1.dnssrvr.comIf you get the same response (not found: 3(NXDOMAIN)), then no reverse dns record exists for this ip address.