Hi all,
I have recently installed ZCS OS 5.0.9 64bit edition on Ubuntu 8.04.1 64bit. During initial testing everything appeared to be working fine, however we noticed we were losing emails from a few customers.
Upon further checking, I determined it was some sort of timeout error. We were using MXLogic for spam filtering, and when I had them try to directly send email to us, I got the same timeout errors.
They have been unable to resolve the issue, and I have found nothing specifically related to my problem on the forums. If anybody can be of help, I would be greatly appreciative!
Log lines follow:

Oct 20 19:51:25 mail postfix/smtpd[26426]: connect from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:51:25 mail postfix/smtpd[26426]: setting up TLS connection from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:51:25 mail postfix/smtpd[26426]: TLS connection established from mxl145v245.mxlogic.net[208.65.145.245]: TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)
Oct 20 19:51:25 mail postfix/smtpd[26426]: CDFF0158200B: client=mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:51:47 mail postfix/smtpd[26436]: connect from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:51:47 mail postfix/smtpd[26436]: setting up TLS connection from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:51:47 mail postfix/smtpd[26436]: TLS connection established from mxl145v245.mxlogic.net[208.65.145.245]: TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)
Oct 20 19:51:47 mail postfix/smtpd[26436]: ADA4B158200C: client=mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:51:59 mail postfix/smtpd[20536]: timeout after DATA from mxl144v245.mxlogic.net[208.65.144.245]
Oct 20 19:51:59 mail postfix/smtpd[20536]: disconnect from mxl144v245.mxlogic.net[208.65.144.245]
Oct 20 19:52:02 mail zmmailboxdmgr[26611]: status requested
Oct 20 19:52:02 mail zmmailboxdmgr[26611]: status OK
Oct 20 19:52:05 mail postfix/smtpd[20536]: connect from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:52:05 mail postfix/smtpd[20536]: setting up TLS connection from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:52:05 mail postfix/smtpd[20536]: TLS connection established from mxl145v245.mxlogic.net[208.65.145.245]: TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)
Oct 20 19:52:06 mail postfix/smtpd[20536]: 1B0011582001: client=mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:52:14 mail postfix/anvil[9327]: statistics: max connection rate 6/60s for (smtp:208.65.145.245) at Oct 20 19:50:07
Oct 20 19:52:14 mail postfix/anvil[9327]: statistics: max connection count 12 for (smtp:208.65.145.245) at Oct 20 19:52:05
Oct 20 19:52:14 mail postfix/anvil[9327]: statistics: max cache size 2 at Oct 20 19:49:32
Oct 20 19:52:24 mail zmmailboxdmgr[27085]: status requested
Oct 20 19:52:24 mail zmmailboxdmgr[27085]: status OK
Oct 20 19:52:25 mail zmmailboxdmgr[27153]: status requested
Oct 20 19:52:25 mail zmmailboxdmgr[27153]: status OK
Oct 20 19:53:32 mail zmmailboxdmgr[27562]: status requested
Oct 20 19:53:32 mail zmmailboxdmgr[27562]: status OK
Oct 20 19:53:32 mail zmmailboxdmgr[27630]: status requested
Oct 20 19:53:32 mail zmmailboxdmgr[27630]: status OK
Oct 20 19:54:02 mail zmmailboxdmgr[27834]: status requested
Oct 20 19:54:02 mail zmmailboxdmgr[27834]: status OK
Oct 20 19:54:33 mail postfix/smtpd[24984]: warning: network_biopair_interop: error reading 5 bytes from the network: Connection reset by peer
Oct 20 19:54:33 mail postfix/smtpd[24984]: timeout after DATA from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:54:33 mail postfix/smtpd[24984]: disconnect from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:54:33 mail postfix/smtpd[24985]: warning: network_biopair_interop: error reading 5 bytes from the network: Connection reset by peer
Oct 20 19:54:33 mail postfix/smtpd[24985]: timeout after DATA from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:54:33 mail postfix/smtpd[24985]: disconnect from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:54:33 mail postfix/smtpd[24986]: warning: network_biopair_interop: error reading 5 bytes from the network: Connection reset by peer
Oct 20 19:54:33 mail postfix/smtpd[24986]: timeout after DATA from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:54:33 mail postfix/smtpd[24986]: disconnect from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:54:39 mail zmmailboxdmgr[28314]: status requested
Oct 20 19:54:39 mail zmmailboxdmgr[28314]: status OK
Oct 20 19:54:39 mail zmmailboxdmgr[28382]: status requested
Oct 20 19:54:39 mail zmmailboxdmgr[28382]: status OK
Oct 20 19:55:08 mail postfix/smtpd[25677]: warning: network_biopair_interop: error reading 5 bytes from the network: Connection reset by peer
Oct 20 19:55:08 mail postfix/smtpd[25677]: timeout after DATA from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:55:08 mail postfix/smtpd[25677]: disconnect from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:55:08 mail postfix/smtpd[25676]: warning: network_biopair_interop: error reading 5 bytes from the network: Connection reset by peer
Oct 20 19:55:08 mail postfix/smtpd[25676]: timeout after DATA from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:55:08 mail postfix/smtpd[25676]: disconnect from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:55:08 mail postfix/smtpd[25678]: warning: network_biopair_interop: error reading 5 bytes from the network: Connection reset by peer
Oct 20 19:55:08 mail postfix/smtpd[25678]: timeout after DATA from mxl145v245.mxlogic.net[208.65.145.245]
Oct 20 19:55:08 mail postfix/smtpd[25678]: disconnect from mxl145v245.mxlogic.net[208.65.145.245]
O