I had Postfix installed on CentOS earlier (several months ago) and it was working fine. Due to the fact of the many brute-force attempts and considering that I didn't use it almost at all I shut Postfix down.
Now I needed to use it, and when I started and tested it: it can receive emails fine, but not send. I tried to send emails to yahoo, google, hotmail, mail.ru, yandex.ru and the result was the same:
postfix/smtp[30799]: 3EA0C11A82FD: to=<i********@gmail.com>, relay=alt4.gmail-smtp-in.l.google.com[74.125.93.27]:25, delay=0.56, delays=0.02/0.01/0.53/0, dsn=4.4.2, status=deferred (lost connection with alt4.gmail-smtp-in.l.google.com[74.125.93.27] while receiving the initial server greeting)
Also there are lines like this:
postfix/smtp[31728]: C792711A82EB: conversation with gmail-smtp-in.l.google.com[74.125.39.27] timed out while performing the EHLO handshake
The only place where I could send emails is mail.md
I re-installed Postfix but nothing changed.
Tried to disable firewall without any luck.
My IP is not listed/blocked.
The configuration is almost default, just the changes described at http://wiki.centos.org/HowTos/postfix which worked earlier.
Checked the SMTP server at mxtoolbox.com. The result is:
220 host-static-x-x-x-x.moldtelecom.md ESMTP Postfix
OK - x-x-x-x resolves to host-static-x-x-x-x.moldtelecom.md
OK - Reverse DNS matches SMTP Banner
0 seconds - Good on Connection time
Not an open relay.
1.139 seconds - Good on Transaction time
Session Transcript:
HELO please-read-policy.mxtoolbox.com
250 host-static-x-x-x-x.moldtelecom.md [172 ms]
MAIL FROM: <supertool@mxtoolbox.com>
250 2.1.0 Ok [172 ms]
RCPT TO: <test@example.com>
554 5.7.1 <test@example.com>: Relay access denied [172 ms]
QUIT
221 2.0.0 Bye [172 ms]
There is one strange thing (or maybe not?). When I telnet to my smtp server and try the HELO command I gen an error first time. But it responds ok the second time:
220 host-static-x-x-x-x.moldtelecom.md ESMTP Postfix
HELO somedomain.com
502 5.5.2 Error: command not recognized
HELO somedomain.com
250 host-static-x-x-x-x.moldtelecom.md
Does anybody have any idea what could be wrong?
UPDATE
I have increased the debug level. Here are some logs:
postfix/master[3433]: daemon started -- version 2.3.3, configuration /etc/postfix
postfix/qmgr[3436]: AF95C11A82ED: from=<a****n@i***d.com>, size=597, nrcpt=1 (queue active)
postfix/qmgr[3436]: 89DE011A82EB: from=<a****n@i***d.com>, size=597, nrcpt=1 (queue active)
postfix/smtp[3439]: vstream_buf_get_ready: fd 11 got 45
postfix/smtp[3439]: < gmail-smtp-in.l.google.com[74.125.39.27]: 220 mx.google.com ESMTP a13si2222396fak.134
postfix/smtp[3439]: > gmail-smtp-in.l.google.com[74.125.39.27]: EHLO host-static-x-x-x-x.moldtelecom.md
postfix/smtp[3439]: vstream_fflush_some: fd 11 flush 49
postfix/smtp[3438]: smtp_get: EOF
postfix/smtp[3438]: AF95C11A82ED: lost connection with d.mx.mail.yahoo.com[209.191.88.254] while receiving the initial server greeting
postfix/smtp[3438]: smtp_get: EOF
postfix/smtp[3438]: AF95C11A82ED: lost connection with e.mx.mail.yahoo.com[67.195.168.230] while receiving the initial server greeting
postfix/smtp[3438]: smtp_get: EOF
postfix/smtp[3438]: AF95C11A82ED: lost connection with b.mx.mail.yahoo.com[74.6.136.65] while receiving the initial server greeting
postfix/smtp[3438]: smtp_get: EOF
postfix/smtp[3438]: AF95C11A82ED: lost connection with g.mx.mail.yahoo.com[98.137.54.238] while receiving the initial server greeting
postfix/smtp[3438]: smtp_get: EOF
postfix/smtp[3438]: connect to subsystem private/defer
postfix/smtp[3438]: send attr nrequest = 0
postfix/smtp[3438]: send attr flags = 0
postfix/smtp[3438]: send attr queue_id = AF95C11A82ED
postfix/smtp[3438]: send attr original_recipient = ib****ri@yahoo.com
postfix/smtp[3438]: send attr recipient = ib****ri@yahoo.com
postfix/smtp[3438]: send attr offset = 448
postfix/smtp[3438]: send attr dsn_orig_rcpt = rfc822;ib****ri@yahoo.com
postfix/smtp[3438]: send attr notify_flags = 0
postfix/smtp[3438]: send attr status = 4.4.2
postfix/smtp[3438]: send attr diag_type =
postfix/smtp[3438]: send attr diag_text =
postfix/smtp[3438]: send attr mta_type =
postfix/smtp[3438]: send attr mta_mname =
postfix/smtp[3438]: send attr action = delayed
postfix/smtp[3438]: send attr reason = lost connection with a.mx.mail.yahoo.com[67.195.168.31] while receiving the initial server greeting
postfix/smtp[3438]: private/defer socket: wanted attribute: status
postfix/smtp[3438]: vstream_fflush_some: fd 12 flush 353
postfix/smtp[3438]: vstream_buf_get_ready: fd 12 got 10
postfix/smtp[3438]: input attribute name: status
postfix/smtp[3438]: input attribute value: 0
postfix/smtp[3438]: private/defer socket: wanted attribute: (list terminator)
postfix/smtp[3438]: input attribute name: (end)
postfix/smtp[3438]: AF95C11A82ED: to=<ib****ri@yahoo.com>, relay=a.mx.mail.yahoo.com[67.195.168.31]:25, delay=214, delays=213/0.03/0.77/0, dsn=4.4.2, status=deferred (lost connection with a.mx.mail.yahoo.com[67.195.168.31] while receiving the initial server greeting)
postfix/smtp[3438]: flush_add: site yahoo.com id AF95C11A82ED
postfix/smtp[3438]: match_list_match: yahoo.com: no match
postfix/smtp[3438]: flush_add: site yahoo.com id AF95C11A82ED status 4
UPDATE 2
It seems that that Postfix can send messages to all the servers inside my country, but can not to the servers outside my country. The only difference (found by mailq) between the outside and the inside ones is that the traceroute to outside servers is going through 10.1.74.xx but to inside ones not. I contacted my ISP and they say that they do not block/filter anything, and the only thing they suggested is that I need a PTR record (which can not be the problem).
traceroute:
[root@in-md ~]# traceroute mail.google.com
traceroute to mail.google.com (74.125.39.19), 30 hops max, 40 byte packets
1 host-static-109-185-171-1.moldtelecom.md (109.185.171.1) 0.334 ms 0.330 ms 0.264 ms
2 46.74.1.10.in-addr.arpa (10.1.74.46) 0.792 ms 0.795 ms 0.733 ms
3 host-static-86-106-213-29.moldtelecom.md (86.106.213.29) 1.005 ms 0.875 ms 0.928 ms
4 host-static-86-106-213-30.moldtelecom.md (86.106.213.30) 0.829 ms 0.807 ms 0.811 ms
5 host-static-212-0-199-5.moldtelecom.md (212.0.199.5) 3.959 ms 3.935 ms 3.896 ms
6 host-static-212-0-200-146.moldtelecom.md (212.0.200.146) 2.116 ms 2.133 ms 2.145 ms
7 core1.ams.net.google.com (195.69.144.247) 46.458 ms 46.559 ms 46.499 ms
8 209.85.248.88 (209.85.248.88) 47.109 ms 209.85.248.93 (209.85.248.93) 47.279 ms 209.85.248.88 (209.85.248.88) 47.119 ms
9 209.85.250.141 (209.85.250.141) 54.194 ms 209.85.248.183 (209.85.248.183) 53.980 ms 54.124 ms
10 209.85.254.118 (209.85.254.118) 53.251 ms 53.448 ms 53.849 ms
11 209.85.249.162 (209.85.249.162) 53.631 ms * *
12 fx-in-f19.1e100.net (74.125.39.19) 53.941 ms 54.141 ms 53.749 ms
[root@in-md ~]# traceroute mail.md
traceroute to mail.md (178.17.163.132), 30 hops max, 40 byte packets
1 host-static-109-185-171-1.moldtelecom.md (109.185.171.1) 0.302 ms 0.319 ms 0.243 ms
2 host-static-212-0-192-114.moldtelecom.md (212.0.192.114) 0.986 ms 0.983 ms 0.938 ms
3 host-static-212-0-192-113.moldtelecom.md (212.0.192.113) 1.499 ms 1.366 ms 1.294 ms
4 in-orange.ch.md.trabia.net (195.22.253.10) 1.113 ms 1.080 ms 1.112 ms
5 mx3.mail.md (178.17.163.132) 1.115 ms 1.084 ms 1.043 ms
tcptraceroute:
[root@in-md ~]# tcptraceroute mail.google.com
traceroute to mail.google.com (74.125.39.17), 30 hops max, 40 byte packets
1 host-static-109-185-171-1.moldtelecom.md (109.185.171.1) 0.292 ms 0.267 ms 0.252 ms
2 46.74.1.10.in-addr.arpa (10.1.74.46) 0.812 ms 0.735 ms 0.727 ms
3 host-static-86-106-213-29.moldtelecom.md (86.106.213.29) 0.949 ms 0.861 ms 0.906 ms
4 host-static-86-106-213-30.moldtelecom.md (86.106.213.30) 0.810 ms 0.783 ms 0.828 ms
5 host-static-212-0-199-9.moldtelecom.md (212.0.199.9) 3.766 ms 3.451 ms 3.306 ms
6 host-static-212-0-200-146.moldtelecom.md (212.0.200.146) 2.404 ms 2.243 ms 2.057 ms
7 * * *
8 209.85.248.93 (209.85.248.93) 47.100 ms 46.942 ms 46.986 ms
9 209.85.250.141 (209.85.250.141) 54.503 ms 209.85.248.183 (209.85.248.183) 55.067 ms 54.148 ms
10 209.85.254.114 (209.85.254.114) 53.423 ms 209.85.254.116 (209.85.254.116) 54.150 ms 209.85.254.118 (209.85.254.118) 53.800 ms
11 209.85.254.134 (209.85.254.134) 3060.001 ms * 209.85.254.134 (209.85.254.134) 53.877 ms
12 * * *
13 * * *
14 * * *
15 * * *
16 fx-in-f17.1e100.net (74.125.39.17) 54.176 ms 54.156 ms 54.656 ms
[root@in-md ~]# tcptraceroute mail.md
traceroute to mail.md (178.17.163.132), 30 hops max, 40 byte packets
1 host-static-109-185-171-1.moldtelecom.md (109.185.171.1) 0.371 ms 0.302 ms 0.231 ms
2 host-static-212-0-192-114.moldtelecom.md (212.0.192.114) 0.998 ms 1.011 ms 0.968 ms
3 host-static-212-0-192-113.moldtelecom.md (212.0.192.113) 1.456 ms 1.184 ms 0.977 ms
4 in-orange.ch.md.trabia.net (195.22.253.10) 1.167 ms 1.143 ms 1.391 ms
5 mx3.mail.md (178.17.163.132) 1.908 ms 2.439 ms 2.252 ms
Best Answer
You don't have a problem with your SMTP daemon but with your SMTP client. It's not a problem when you connect to YOUR server but when you connect to OTHER servers.
So try to
telnet 74.125.39.27 25and look how far you come. As others can connect to Google or whatever it must be something with your network. Do you have a firewall that blocks outgoing SMTP on port 25? Does your provider block port 25?Postfix tries to connect to other servers and the connection cannot be established. Either in case of your side blocks the connection or on the other hand the destination server refuses the connection. But as I said it is not Postfix related but network related.
Edit: I will not blame anybody. But after a short remote session one could see that someone blocks SMTP traffic to hosts outside of .md. And it is not the firewall! Further diagnosis can't be made even from the server itself.