Hi,
i don't know i i'm right here, but i try to get help for ur customers.
We are a Internetprovider with about 20.000 EMail-Customers. We are using Postfix on your Servers and had many times Problems to reach your Servers or get Mails from you.
I see in our Logfile this:
2015-10-14T19:32:17.848823+02:00 mailbkupXX postfix/smtpd[938]: warning: hostname mail1.bemta5.messagelabs.com does not resolve to address 195.245.231.147: Name or service not known
2015-10-14T20:02:21.496317+02:00 mailbkupXX postfix/smtpd[5357]: warning: hostname mail1.bemta5.messagelabs.com does not resolve to address 195.245.231.147: Name or service not known
2015-10-15T06:22:57.881913+02:00 mailbkupXX postfix/smtpd[12651]: warning: hostname mail1.bemta14.messagelabs.com does not resolve to address 193.109.254.105: Name or service not known
2015-10-15T06:49:14.680725+02:00 mailbkupXX postfix/smtpd[15154]: warning: hostname mail1.bemta14.messagelabs.com does not resolve to address 193.109.254.118: Name or service not known
and many Times this:
Oct 14 22:13:38 HOST postfix/smtpd[5012]: lost connection after CONNECT from mail1.bemta3.messagelabs.com[195.245.230.176]
Oct 14 22:13:58 HOST postfix/smtpd[14884]: lost connection after RCPT from mail1.bemta3.messagelabs.com[195.245.230.172]
Oct 14 22:24:33 HOST postfix/smtpd[5012]: lost connection after CONNECT from mail1.bemta7.messagelabs.com[216.82.254.112]
Oct 14 22:38:58 HOST postfix/smtpd[20481]: lost connection after CONNECT from mail1.bemta3.messagelabs.com[195.245.230.169]
Oct 14 22:44:20 HOST postfix/smtpd[17216]: lost connection after RCPT from mail1.bemta5.messagelabs.com[195.245.231.149]
Oct 14 23:18:19 HOST postfix/smtpd[4189]: lost connection after RCPT from mail1.bemta14.messagelabs.com[193.109.254.107]
Oct 14 23:35:09 HOST postfix/smtpd[4427]: lost connection after RCPT from mail1.bemta5.messagelabs.com[195.245.231.147]
Oct 14 23:50:47 HOST postfix/smtpd[17240]: lost connection after RCPT from mail1.bemta12.messagelabs.com[216.82.251.6]
Oct 15 00:02:16 HOST postfix/smtpd[22467]: lost connection after CONNECT from mail1.bemta12.messagelabs.com[216.82.251.7]
Oct 15 00:03:50 HOST postfix/smtpd[20488]: lost connection after RCPT from mail1.bemta5.messagelabs.com[195.245.231.142]
Oct 15 00:12:14 HOST postfix/smtpd[23155]: lost connection after CONNECT from mail1.bemta3.messagelabs.com[195.245.230.161]
Oct 15 00:18:20 HOST postfix/smtpd[22467]: lost connection after RCPT from mail1.bemta5.messagelabs.com[195.245.231.145]
Oct 15 00:29:37 HOST postfix/smtpd[31041]: lost connection after RCPT from mail1.bemta5.messagelabs.com[195.245.231.139]
Oct 15 00:50:49 HOST postfix/smtpd[6541]: lost connection after RCPT from mail1.bemta5.messagelabs.com[195.245.231.145]
Oct 15 00:56:36 HOST postfix/smtpd[32146]: lost connection after RCPT from mail1.bemta3.messagelabs.com[195.245.230.172]
Oct 15 01:16:54 HOST postfix/smtpd[14289]: lost connection after RCPT from mail1.bemta12.messagelabs.com[216.82.251.15]
Oct 15 01:48:52 HOST postfix/smtpd[14135]: lost connection after CONNECT from mail1.bemta5.messagelabs.com[195.245.231.140]
Oct 15 01:54:25 HOST postfix/smtpd[29473]: lost connection after RCPT from mail1.bemta7.messagelabs.com[216.82.254.112]
Oct 15 01:56:02 HOST postfix/smtpd[28477]: lost connection after RCPT from mail1.bemta14.messagelabs.com[193.109.254.115]
Oct 15 01:57:31 HOST postfix/smtpd[14135]: lost connection after CONNECT from mail1.bemta14.messagelabs.com[193.109.254.116]
Oct 15 02:03:55 HOST postfix/smtpd[32277]: lost connection after RCPT from mail1.bemta12.messagelabs.com[216.82.251.15]
Oct 15 02:04:50 HOST postfix/smtpd[30292]: lost connection after CONNECT from mail1.bemta14.messagelabs.com[193.109.254.114]
Oct 15 02:15:19 HOST postfix/smtpd[32277]: lost connection after CONNECT from mail1.bemta14.messagelabs.com[193.109.254.117]
Oct 15 02:24:41 HOST postfix/smtpd[30292]: lost connection after CONNECT from mail1.bemta14.messagelabs.com[193.109.254.105]
Oct 15 02:42:06 HOST postfix/smtpd[2003]: lost connection after CONNECT from mail1.bemta5.messagelabs.com[195.245.231.148]
Oct 15 02:50:03 HOST postfix/smtpd[30292]: lost connection after RCPT from mail1.bemta5.messagelabs.com[195.245.231.141]
Oct 15 02:55:27 HOST postfix/smtpd[27523]: lost connection after CONNECT from mail1.bemta12.messagelabs.com[216.82.251.15]
Oct 15 02:57:54 HOST postfix/smtpd[25206]: lost connection after CONNECT from mail1.bemta14.messagelabs.com[193.109.254.112]
Oct 15 03:01:02 HOST postfix/smtpd[30681]: lost connection after RCPT from mail1.bemta7.messagelabs.com[216.82.254.113]
Oct 15 03:16:10 HOST postfix/smtpd[2945]: lost connection after RCPT from mail1.bemta3.messagelabs.com[195.245.230.161]
Oct 15 03:22:56 HOST postfix/smtpd[30681]: lost connection after CONNECT from mail1.bemta14.messagelabs.com[193.109.254.114]
Oct 15 03:26:01 HOST postfix/smtpd[5046]: lost connection after RCPT from mail1.bemta14.messagelabs.com[193.109.254.109]
Oct 15 03:56:59 HOST postfix/smtpd[15106]: lost connection after CONNECT from mail1.bemta5.messagelabs.com[195.245.231.149]
Oct 15 04:00:34 HOST postfix/smtpd[17159]: lost connection after RCPT from mail1.bemta3.messagelabs.com[195.245.230.164]
Oct 15 04:07:37 HOST postfix/smtpd[15106]: lost connection after CONNECT from mail1.bemta14.messagelabs.com[193.109.254.105]
Oct 15 04:17:14 HOST postfix/smtpd[15106]: lost connection after CONNECT from mail1.bemta14.messagelabs.com[193.109.254.113]
Oct 15 04:22:04 HOST postfix/smtpd[26417]: lost connection after RCPT from mail1.bemta14.messagelabs.com[193.109.254.115]
Oct 15 04:31:58 HOST postfix/smtpd[29773]: lost connection after RCPT from mail1.bemta14.messagelabs.com[193.109.254.108]
Oct 15 04:35:38 HOST postfix/smtpd[26417]: lost connection after RCPT from mail1.bemta3.messagelabs.com[195.245.230.162]
Oct 15 04:42:56 HOST postfix/smtpd[32093]: lost connection after CONNECT from mail1.bemta12.messagelabs.com[216.82.251.15]
Oct 15 05:24:00 HOST postfix/smtpd[16840]: lost connection after CONNECT from mail1.bemta3.messagelabs.com[195.245.230.169]
Oct 15 05:33:52 HOST postfix/smtpd[9135]: lost connection after RCPT from mail1.bemta14.messagelabs.com[193.109.254.112]
Oct 15 05:40:24 HOST postfix/smtpd[22507]: lost connection after CONNECT from mail1.bemta7.messagelabs.com[216.82.254.99]
Oct 15 06:06:17 HOST postfix/smtpd[22507]: lost connection after CONNECT from mail1.bemta7.messagelabs.com[216.82.254.99]
Oct 15 06:07:12 HOST postfix/smtpd[913]: lost connection after RCPT from mail1.bemta12.messagelabs.com[216.82.251.4]
Oct 15 06:37:18 HOST postfix/smtpd[6351]: lost connection after CONNECT from mail1.bemta7.messagelabs.com[216.82.254.99]
Oct 15 06:57:26 HOST postfix/smtpd[14373]: lost connection after CONNECT from mail1.bemta5.messagelabs.com[195.245.231.147]
This Problem is on multiple Servers at us.
I found other links like the same (?) problem:
http://www.symantec.com/connect/forums/messagelabs-delaying-email
http://www.emaildiscussions.com/showthread.php?t=64228
How do we resolve this problem?
For other Infos a attached a MDR from your Customer.
Thanks a lot.