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-   -   Postfix problem: lost connection after CONNECT from unknown (http://www.howtoforge.com/forums/showthread.php?t=17726)

fernando_torrez 26th November 2007 22:10

Postfix problem: lost connection after CONNECT from unknown
 
Hi everybody

I'm fighting with a terrible problem for 1 month. sometimes, when a client tried to send mails the server sends this error:

Sending of message failed.
The message could not be sent because connecting to SMTP server myserver.com failed. The server may be unavailable or is refusing SMTP connections. Please verify that your SMTP server setting is correct and try again, or else contact your network administrator

I saw the postfix log and found that for some reason the connection is closed before the message is processed. this is a piece of the postfix log file:


Nov 26 08:52:36 mail postfix/smtpd[2241]: connect from unknown[192.168.0.2]
Nov 26 08:52:36 mail postfix/smtpd[2241]: lost connection after CONNECT from unknown[192.168.0.2]
Nov 26 08:52:36 mail postfix/smtpd[2241]: disconnect from unknown[192.168.0.2]

it means that for some reason a local client is losing the connection with myserver, then the client tries to send 3 more times (or so) before the message is sent, and in the worst cases I restart the whole mail server (reboot de server).
this is appending once a day... lately .... and I'm so :mad:


Here is a larger piece of the postfix log file:

Nov 26 08:55:07 mail postfix/smtpd[2342]: connect from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2342]: lost connection after CONNECT from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2342]: disconnect from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2291]: connect from unknown[125.134.123.148]
Nov 26 08:55:07 mail postfix/smtpd[2291]: lost connection after CONNECT from unknown[125.134.123.148]
Nov 26 08:55:07 mail postfix/smtpd[2291]: disconnect from unknown[125.134.123.148]
Nov 26 08:55:07 mail postfix/smtpd[2342]: connect from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2342]: lost connection after CONNECT from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2342]: disconnect from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2291]: connect from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2291]: lost connection after CONNECT from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2291]: disconnect from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2342]: connect from unknown[192.168.0.2]
Nov 26 08:55:07 mail postfix/smtpd[2342]: lost connection after CONNECT from unknown[192.168.0.2]
Nov 26 08:55:07 mail postfix/smtpd[2342]: disconnect from unknown[192.168.0.2]
Nov 26 08:55:07 mail postfix/smtpd[2342]: connect from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2342]: lost connection after CONNECT from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2342]: disconnect from unknown[87.226.180.6]
Nov 26 08:55:07 mail postfix/smtpd[2295]: disconnect from unknown[125.134.123.148]
Nov 26 08:55:07 mail postfix/smtpd[2291]: warning: 62.105.25.12: hostname adsl-ppp-12.reus.ru verification failed: Host not found
Nov 26 08:55:07 mail postfix/smtpd[2291]: connect from unknown[62.105.25.12]
Nov 26 08:55:07 mail postfix/smtpd[2291]: lost connection after CONNECT from unknown[62.105.25.12]
Nov 26 08:55:07 mail postfix/smtpd[2291]: disconnect from unknown[62.105.25.12]
Nov 26 08:55:07 mail postfix/smtpd[2342]: warning: 62.105.25.12: hostname adsl-ppp-12.reus.ru verification failed: Host not found
Nov 26 08:55:07 mail postfix/smtpd[2342]: connect from unknown[62.105.25.12]
Nov 26 08:55:07 mail postfix/smtpd[2295]: warning: 62.105.25.12: hostname adsl-ppp-12.reus.ru verification failed: Host not found
Nov 26 08:55:07 mail postfix/smtpd[2295]: connect from unknown[62.105.25.12]
Nov 26 08:55:07 mail postfix/smtpd[2295]: lost connection after CONNECT from unknown[62.105.25.12]
Nov 26 08:55:07 mail postfix/smtpd[2295]: disconnect from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2291]: warning: 62.105.25.12: hostname adsl-ppp-12.reus.ru verification failed: Host not found
Nov 26 08:55:08 mail postfix/smtpd[2291]: connect from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2291]: lost connection after CONNECT from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2291]: disconnect from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2295]: warning: 62.105.25.12: hostname adsl-ppp-12.reus.ru verification failed: Host not found
Nov 26 08:55:08 mail postfix/smtpd[2295]: connect from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2295]: lost connection after CONNECT from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2295]: disconnect from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2291]: warning: 62.105.25.12: hostname adsl-ppp-12.reus.ru verification failed: Host not found
Nov 26 08:55:08 mail postfix/smtpd[2291]: connect from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2291]: lost connection after CONNECT from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2291]: disconnect from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2295]: warning: 62.105.25.12: hostname adsl-ppp-12.reus.ru verification failed: Host not found
Nov 26 08:55:08 mail postfix/smtpd[2295]: connect from unknown[62.105.25.12]
Nov 26 08:55:08 mail postfix/smtpd[2295]: lost connection after CONNECT from unknown[62.105.25.12]


It seem that the postfix is rejecting either internal an external mails :(


here's is my postfix configuration (postconf -n)

alias_database = hash:/etc/aliases
alias_maps = hash:/etc/aliases, ldap:ldapaliases
body_checks = pcre:/etc/postfix/body_checks
canonical_maps = hash:/etc/postfix/canonical
command_directory = /usr/sbin
daemon_directory = /usr/lib/postfix
debug_peer_level = 2
default_destination_concurrency_limit = 10
default_privs = nobody
defer_transports =
disable_dns_lookups = no
header_checks = pcre:/etc/postfix/header_checks
local_destination_concurrency_limit = 2
mail_name = Postfix on SuSE Linux eMail Server 3.1
mail_owner = postfix
mailbox_transport = lmtp:unix:public/lmtp
masquerade_domains = $mydomain
masquerade_exceptions = root
maximal_queue_lifetime = 2d
message_size_limit = 10485760
mydestination = $mydomain, $myhostname, localhost.$mydomain, [190.129.91.2]
myhostname = mail.bago.com.bo
myorigin = $mydomain
program_directory = /usr/lib/postfix
queue_directory = /var/spool/postfix
recipient_delimiter = +
relayhost =
relocated_maps = hash:/etc/postfix/relocated
sender_canonical_maps = ldap:ldapcanonical
smtp_tls_loglevel = 0
smtp_tls_note_starttls_offer = yes
smtp_tls_session_cache_database = sdbm:/etc/postfix/smtp_scache
smtpd_banner = $myhostname ESMTP $mail_name
smtpd_client_restrictions = permit_sasl_authenticated
smtpd_recipient_restrictions = ldap:ldapmailenab, permit_tls_clientcerts, permit_sasl_authenticated, permit_mynetworks, check_client_access btree:/etc/postfix/dracd, check_sender_access hash:/etc/postfix/access_usernames, check_recipient_access hash:/etc/postfix/access_usernames, check_relay_domains
smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous
smtpd_sender_restrictions = hash:/etc/postfix/access_usernames
smtpd_tls_ask_ccert = yes
smtpd_tls_received_header = yes
smtpd_tls_session_cache_database = sdbm:/etc/postfix/smtpd_scache
tls_daemon_random_source = dev:/dev/urandom
tls_random_source = dev:/dev/urandom
transport_maps = hash:/etc/postfix/transport
virtual_maps = hash:/etc/postfix/virtual, ldap:ldapvuser


and this is my master.cf

smtp inet n - y - - smtpd
localhost:10025 inet n - n - - smtpd -o content_filter=
smtps inet n - y - - smtpd -o smtpd_tls_wrappermode=yes -o smtpd_sasl_auth_enable=yes
pickup unix n n y 60 1 pickup
cleanup unix - - y - 0 cleanup
qmgr unix n - y 300 1 qmgr
tlsmgr fifo - - n 300 1 tlsmgr
rewrite unix - - y - - trivial-rewrite
bounce unix - - y - 0 bounce
defer unix - - y - 0 bounce
flush unix - - n 1000? 0 flush
smtp unix - - y - - smtp
showq unix n - y - - showq
error unix - - y - - error
local unix - n n - - local
lmtp unix - - y - - lmtp
cyrus unix - n n - - pipe
flags=R user=cyrus argv=/cyrus/bin/deliver -e -m ${extension} ${user}
uucp unix - n n - - pipe
flags=F user=uucp argv=uux -r -n -z -a$sender - $nexthop!rmail ($recipient)
ifmail unix - n n - - pipe
flags=F user=ftn argv=/usr/lib/ifmail/ifmail -r $nexthop ($recipient)
bsmtp unix - n n - - pipe
flags=F. user=foo argv=/usr/local/sbin/bsmtp -f $sender $nexthop $recipient
procmail unix - n n - - pipe
flags=R user=cyrus argv=/usr/bin/procmail -t -m USER=${user} EXT=${extension} /etc/procmailrc

I'll really appreciate any help

Thanks in advance

falko 27th November 2007 18:58

What'S the output of
Code:

telnet localhost 25
? Are there any other errors in your logs? What's the output of
Code:

postconf -d|grep mydomain
?

fernando_torrez 27th November 2007 21:30

re: Postfix problem: lost connection after CONNECT from unknown
 
I run (telnet from a client PC)
telnet mail.myserver.com.bo
and after 45 seconds a got this message:

220 mail.myserver.com.bo ESMTP Postfix on SuSE Linux eMail Server 3.1


I also run the code: postconf -d | grep mydomain
and this is the output:

append_dot_mydomain = yes
mydestination = $myhostname, localhost.$mydomain
mydomain = mail

I also verified 'myhostaname' parameter, it's set with a fqdn

myhostname = mail.myserver.com.bo


I checked the postfix mail log with this command:

cat mail | grep -ie 'reject' -ie 'warn' -ie 'fatal' -ie ' error'

and got messages like these

Nov 27 00:15:12 mail postfix/smtp[25615]: 4EC5612F9DD: to=<jr_sandre@uol.com.br>, relay=mx.uol.com.br[200.221.29.129], delay=7386, status=deferred (host mx.uol.com.br[200.221.29.129] said: 450 Client host rejected: cannot find your hostname, [190.129.91.2])
Nov 27 00:15:12 mail postfix/smtp[25587]: warning: no MX host for musichannel.com has a valid A record
Nov 27 00:15:12 mail postfix/smtp[25587]: C60DC12FB7E: to=<Jama@musichannel.com>, relay=none, delay=7299, status=deferred (Name service error for dev.null: Host not found)
Nov 27 00:15:12 mail postfix/smtp[25589]: 44C9912FADF: to=<jr_sandre@uol.com.br>, relay=mx.uol.com.br[200.221.29.129], delay=7337, status=deferred (host mx.uol.com.br[200.221.29.129] said: 450 Client host rejected: cannot find your hostname, [190.129.91.2])
Nov 27 00:15:12 mail postfix/smtp[25591]: 911B712F9B5: to=<jr_sandre@uol.com.br>, relay=mx.uol.com.br[200.221.29.129], delay=7408, status=deferred (host mx.uol.com.br[200.221.29.129] said: 450 Client host rejected: cannot find your hostname, [190.129.91.2])
Nov 27 00:15:28 mail postfix/smtp[25331]: CAC6012F9FF: to=<Walter299@thutrang.info>, relay=none, delay=3501, status=deferred (Name service error for thutrang.info: Host not found, try again)
Nov 27 00:16:38 mail postfix/smtpd[25694]: warning: 85.96.218.50: hostname dsl.dynamic859621850.ttnet.net.tr verification failed: Host not found
Nov 27 00:17:06 mail postfix/smtpd[25710]: warning: 87.13.130.36: hostname host36-130-dynamic.13-87-r.retail.telecomitalia.it verification failed: Host not found
Nov 27 00:17:44 mail postfix/smtp[25589]: D32B312FD5C: to=<Joann753@capitaleducators.com>, relay=smtp-in.his.com[216.194.216.44], delay=36, status=deferred (host smtp-in.his.com[216.194.216.44] said: 451 4.7.1 <Joann753@capitaleducators.com>: Recipient address rejected: Greylisting in effect - you can deliver your mail for capitaleducators.com in 300 seconds ...)
Nov 27 00:19:26 mail postfix/smtpd[25694]: warning: 189.149.118.100: hostname dsl-189-149-118-100.prod-infinitum.com.mx verification failed: Host not found
Nov 27 00:20:26 mail postfix/smtp[25181]: 735B012FE12: to=<jquan@du.edu>, relay=barney.cair.du.edu[130.253.1.27], delay=1064, status=bounced (host barney.cair.du.edu[130.253.1.27] said: 550 5.7.1 <jquan@du.edu>: Recipient address rejected: blocked due to excessive spam)
Nov 27 00:21:02 mail postfix/smtpd[25153]: warning: 200.121.207.10: hostname client-200.121.207.10.speedy.net.pe verification failed: Host not found
...
Nov 27 00:31:51 mail postfix/smtp[26115]: 5B95012F9E8: to=<Gilveryfwo@teamsmile.com>, relay=none, delay=7775, status=deferred (Name service error for smtp: Host not found)
Nov 27 00:31:51 mail postfix/smtp[26132]: A9C4212FDEA: to=<jr.f15@bol.com.br>, relay=mx.bol.com.br[200.221.29.128], delay=3792, status=deferred (host mx.bol.com.br[200.221.29.128] said: 450 Client host rejected: cannot find your hostname, [190.129.91.2])
Nov 27 00:31:54 mail postfix/smtp[26124]: A21CE12FE23: to=<jra@mapfre.com.br>, relay=mailer.mapfre.com.br[200.246.177.30], delay=2, status=bounced (host mailer.mapfre.com.br[200.246.177.30] said: 550 #5.1.0 Rejected by bounce verification.)
Nov 27 00:31:54 mail postfix/smtp[26123]: D847C12FB4B: to=<Marinarocbc@lifelikej.net>, relay=none, delay=7423, status=deferred (Name service error for lifelikej.net: Host not found, try again)
Nov 27 00:31:56 mail postfix/smtp[25980]: warning: no MX host for forhealthyskin.com has a valid A record
Nov 27 00:31:56 mail postfix/smtp[25980]: 7900312FE07: to=<stcovenant.org@forhealthyskin.com>, relay=none, delay=3739, status=deferred (Name service error for dev.null: Host not found)
Nov 27 00:31:58 mail postfix/smtp[26132]: 8748D12FE23: to=<jra@mapfre.com.br>, relay=mailer.mapfre.com.br[200.211.99.154], delay=2, status=bounced (host mailer.mapfre.com.br[200.211.99.154] said: 550 #5.1.0 Rejected by bounce verification.)
Nov 27 00:32:01 mail postfix/smtp[26116]: 22B1012FC67: to=<Mitchnwhnj@dobvod.ru>, relay=none, delay=17674, status=deferred (Name service error for dobvod.ru: Host not found, try again)
Nov 27 00:32:42 mail postfix/smtp[26116]: 0E90D12FE30: to=<jqnlx@carle.com>, relay=mx5.carle.com[199.184.120.181], delay=1, status=bounced (host mx5.carle.com[199.184.120.181] said: 550 5.1.1 <jqnlx@carle.com>: Recipient address rejected: User unknown)
...
Nov 27 00:37:32 mail postfix/smtpd[25985]: warning: 203.113.26.17: hostname 203-113-26-17.totisp.net verification failed: Host not found
Nov 27 00:37:32 mail postfix/smtpd[25972]: warning: 203.113.26.17: hostname 203-113-26-17.totisp.net verification failed: Host not found
Nov 27 00:37:35 mail postfix/smtpd[25971]: warning: 203.113.26.17: hostname 203-113-26-17.totisp.net verification failed: Host not found
...
Nov 27 15:18:27 mail postfix/smtp[13244]: 1704112FE28: to=<jr2004@uol.com.br>, relay=mx.uol.com.br[200.221.29.129], delay=36360, status=deferred (host mx.uol.com.br[200.221.29.129] said: 450 Client host rejected: cannot find your hostname, [190.129.91.2])
Nov 27 15:18:28 mail postfix/smtp[13253]: 1167912FABD: to=<jr2004@uol.com.br>, relay=mx.uol.com.br[200.221.29.129], delay=171420, status=deferred (host mx.uol.com.br[200.221.29.129] said: 450 Client host rejected: cannot find your hostname, [190.129.91.2])
Nov 27 15:18:29 mail postfix/smtp[13277]: 6F3F912FBF9: to=<jquire@dcr.net>, relay=filter2.win.net[216.24.27.102], delay=1671, status=bounced (host filter2.win.net[216.24.27.102] said: 554 5.7.1 <jquire@dcr.net>: Recipient address rejected: User unknown in virtual mailbox table)
Nov 27 15:18:30 mail postfix/smtp[13255]: 64CD712FB17: to=<jr2004@uol.com.br>, relay=mx.uol.com.br[200.221.29.129], delay=171458, status=deferred (host mx.uol.com.br[200.221.29.129] said: 450 Client host rejected: cannot find your hostname, [190.129.91.2])
Nov 27 15:18:31 mail postfix/smtp[13275]: 61A4012FC19: to=<jr2004@uol.com.br>, relay=mx.uol.com.br[200.221.29.129], delay=82894, status=deferred (host mx.uol.com.br[200.221.29.129] said: 450 Client host rejected: cannot find your hostname, [190.129.91.2])
...
Nov 27 15:25:57 mail postfix/smtpd[13515]: warning: 201.53.170.22: hostname c935aa16.virtua.com.br verification failed: Host not found
Nov 27 15:26:04 mail postfix/smtpd[13517]: warning: 201.53.170.22: hostname c935aa16.virtua.com.br verification failed: Host not found
Nov 27 15:26:53 mail postfix/smtpd[13530]: warning: 201.53.170.22: hostname c935aa16.virtua.com.br verification failed: Host not found
Nov 27 15:27:56 mail postfix/smtpd[13546]: warning: 75.148.0.66: hostname 75-148-0-66-WashingtonDC.hfc.comcastbusiness.net verification failed: Host not found
...
Nov 27 15:11:55 mail postfix/smtp[12691]: 5CCBE12FA6C: to=<jra@axel.ocn.ne.jp>, relay=mfgw5.ocn.ad.jp[125.206.187.87], delay=3, status=bounced (host mfgw5.ocn.ad.jp[125.206.187.87] said: 554 5.7.1 <jra@axel.ocn.ne.jp>: Recipient address rejected: Access denied)
Nov 27 15:12:00 mail postfix/smtp[12690]: 63DFC12FA6C: to=<jra@axel.ocn.ne.jp>, relay=mfgw5.ocn.ad.jp[125.206.188.198], delay=3, status=bounced (host mfgw5.ocn.ad.jp[125.206.188.198] said: 554 5.7.1 <jra@axel.ocn.ne.jp>: Recipient address rejected: Access denied)
Nov 27 15:12:00 mail postfix/smtp[12691]: ED6D412F767: to=<jra@axel.ocn.ne.jp>, relay=mfgw5.ocn.ad.jp[125.206.188.199], delay=3, status=bounced (host mfgw5.ocn.ad.jp[125.206.188.199] said: 554 5.7.1 <jra@axel.ocn.ne.jp>: Recipient address rejected: Access denied)
Nov 27 15:12:06 mail postfix/smtp[12690]: 557C412FA6C: to=<jra@axel.ocn.ne.jp>, relay=mfgw5.ocn.ad.jp[125.206.188.198], delay=2, status=bounced (host mfgw5.ocn.ad.jp[125.206.188.198] said: 554 5.7.1 <jra@axel.ocn.ne.jp>: Recipient address rejected: Access denied)
...
Nov 27 15:05:14 mail postfix/qmgr[18780]: 716E612F9D0: to=<jr@jrtr.org>, relay=none, delay=77244, status=deferred (Name service error for jrtr.org: Host not found, try again)
Nov 27 15:05:14 mail postfix/qmgr[18780]: 808E812F9BF: to=<jr@jrtr.org>, relay=none, delay=77230, status=deferred (Name service error for jrtr.org: Host not found, try again)


no fatal errors found

I just saw that postfix log has around 8000 reject or error lines over 104000
it means that around 7 percent of postfix logs implies error o reject messages
I think that this is normal for a postfix with around 150 users


I don't know what else to do...
Any suggestion with be very appreciated

thanks

falko 28th November 2007 16:41

Please try
Code:

postconf -e 'mydomain = mail.bago.com.bo'
/etc/init.d/postfix restart

Also, what's in /etc/resolv.conf?

fernando_torrez 29th November 2007 17:30

Yesterday I did:
postconf -e 'mydomain = mail.bago.com.bo'
/etc/init.d/postfix restart

same results... it still reject some clients

this is the my /etc/resolv.conf
domain bago.com.bo
nameserver 200.87.100.10
nameserver 200.87.100.40

and this is my postfix version:
postfix-20010228pl03-56

At around 3 months the ISP changed our public IP and
I just found that the reverse DNS of the new public IP is not working,
and There's a Lot of spam that is comming to the mail server lately...

Is it posible that those problems are crashing the smtp daemons?

I don't know what else todo


thanks for help

falko 30th November 2007 14:17

Quote:

Originally Posted by fernando_torrez
I just found that the reverse DNS of the new public IP is not working

That could be the problem. Please ask your ISP to update the reverse DNS.

If that doesn't help, I'd try two other nameservers in /etc/resolv.conf.


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