postfix lost connection to mailbox lmtp recently

[jaruwat]

postfix/error[10993]: B80DD3282855: to=<user@mydomain.com>, relay=none, delay=0.09, delays=0.07/0.01/0/0.01, dsn=4.4.2, status=deferred (delivery temporarily suspended: lost connection with server.mydomain.com[ip.ad.dr.ess] while sending end of data -- message may be sent more than once).

My Zimbra OE 7.1.0 got lost connection to lmtp many time after upgrade to last version 7.1.0. It running on Red Hat KVM assigned 4 cored and 8GB of memory Estimated user about 700 users.

I've tried to fine parameter of each modules. last thing is reduce connection of lmtp from postfix only 1 session.

[magneticinduction]

I get this error too. Have you been able to fix it?

[davidrios]

I get this error too. Have you been able to fix it?

I get the same error, ZCS version 6.0.10

[PhD]

im also seeing this about once a week...
i have to restart zmmailboxdctl for it to fix itself then flush the mailq to release the deferred messages.

when this happens - we occasionally have a problem with one or two same users then not being able to log in to the webui...

i came across this - either its an MTU problem, or the firewall is blocking special ICMP packets
http://www.mailinglistarchive.com/po.../msg37315.html