Can't send out email with attachment

[benjamin.lim]

We are experiencing email with attachment can't send out issue. We are on version 6.0.2. There did not seems to have such problem when we used it for last 2+ years - same platform and version. The attachment are just normal pdf (not big files) and there within file size limit. Only 2 external parties currently can't receive such emails with attachment from us. The rest is ok. The system log (/var/log/zimbra.log) shows time out message. However emails without attachment to these affected external parties were ok. Our DNS is hosted by external ISP not by us. So far no changes to that as well.
Can anyone please advice what else can we check to resolve this. Thanks.

[phoenix]

We are experiencing email with attachment can't send out issue. We are on version 6.0.2. There did not seems to have such problem when we used it for last 2+ years - same platform and version. The attachment are just normal pdf (not big files) and there within file size limit. Only 2 external parties currently can't receive such emails with attachment from us. The rest is ok. The system log (/var/log/zimbra.log) shows time out message. However emails without attachment to these affected external parties were ok. Our DNS is hosted by external ISP not by us. So far no changes to that as well.
Can anyone please advice what else can we check to resolve this. Thanks.

You need to post the information from the log files showing when a 'failed' attempt to send an email with attachment is sent.

[benjamin.lim]

Thanks for the quick reply. Please advice which log to use? /var/log/zimbra.log, /opt/zimbra/log/logger_myslow.log or which specific one..as there are a number of log files and we are difficulty understanding which is for what. Thanks in advance.

[benjamin.lim]

to save time, I have attached an extract from /var/log/zimbra.log

I have masked off contact names, domain, IP addresses with fictitious ones without any other changes :- (hope this is helpful)

127:Feb 23 06:48:54 ourmailhostname postfix/smtp[11556]: 3AA20586228: enabling PIX workarounds: disable_esmtp delay_dotcrlf for ourpartner_maildomain.at.ah.clara.ne.jp[partner_IPaddr]:25
133:Feb 23 06:49:03 ourmailhostname postfix/smtp[11557]: 6661B586221: enabling PIX workarounds: disable_esmtp delay_dotcrlf for ourpartner_maildomain.at.ah.clara.ne.jp[partner_IPaddr]:25
134:Feb 23 06:49:13 ourmailhostname postfix/smtp[11557]: 6661B586221: to=<t-personA@ourpartner_maildomain>, relay=ourpartner_maildomain.at.ah.clara.ne.jp[partner_IPaddr]:25, delay=54027, delays=53989/28/0.24/10, dsn=2.6.0, status=sent (250 2.6.0 <20110223T074901+0900-16315-0001> Queued mail for delivery)
153:Feb 23 06:52:02 ourmailhostname postfix/smtp[18054]: 4EAF6586226: to=<personB@ourpartner_maildomain>, relay=ourpartner_maildomain.at.ah.clara.ne.jp[partner_IPaddr]:25, delay=75583, delays=75376/0.02/0.54/206, dsn=4.4.2, status=deferred (conversation with ourpartner_maildomain.at.ah.clara.ne.jp[partner_IPaddr] timed out while sending message body)
154:Feb 23 06:52:02 ourmailhostname postfix/smtp[18054]: 4EAF6586226: to=<personC@ourpartner_maildomain>, relay=ourpartner_maildomain.at.ah.clara.ne.jp[partner_IPaddr]:25, delay=75583, delays=75376/0.02/0.54/206, dsn=4.4.2, status=deferred (conversation with ourpartner_maildomain.at.ah.clara.ne.jp[partner_IPaddr] timed out while sending message body)