nanog mailing list archives
Re: SMTP connection + lost while reading message data (header)
From: William Herrin <bill () herrin us>
Date: Thu, 5 Sep 2013 17:12:59 -0400
On Thu, Sep 5, 2013 at 3:48 PM, Kwas Lee <leekwas () yahoo com> wrote:
Could someone please advice as some of sender are unable to send mails to my server when i check the logs i found 2013-09-05 20:31:32 SMTP connection from smtp-sender.com (senderdomain.com) [xx.xx.xx.xx] lost while reading message data (header)
Hi Lee, Smells like path MTU. The connection died at what is probably the first time in the SMTP session that the remote system tried to send you a large, probably 1500 byte packet: the beginning (message header) part of the data portion (the email message headers and body themselves, as opposed to the sender and recipient declarations). This is not the only candidate cause, but that's what my mind jumps to. Try adjusting the TCP Maximum Segment Size on your server. Turn it down to 1200 or so and see if the problem vanishes. If so, somebody's losing ICMP packets. Regards, Bill Herrin -- William D. Herrin ................ herrin () dirtside com bill () herrin us 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/> Falls Church, VA 22042-3004
Current thread:
- Mail best practices? Deepak Jain (Sep 03)
- Re: Mail best practices? Ted Hatfield (Sep 03)
- SMTP connection + lost while reading message data (header) Kwas Lee (Sep 05)
- Re: SMTP connection + lost while reading message data (header) William Herrin (Sep 05)
- Re: SMTP connection + lost while reading message data (header) Kwas Lee (Sep 05)
- Re: SMTP connection + lost while reading message data (header) William Herrin (Sep 05)