On , wie...@porcupine.org wrote:
post...@nisny.com:
There were several attempts from postfix to connect to 6 different mx
servers to deliver one email. They all have the same result so I'm
only
including the dump of the first here:
We see SYN, SYN|ACK, ACK, and a bunch of retransmissions.
SYN: Initial client window 1400 (scale 6), options [mss
1460,nop,wscale
6,sackOK,TS]
SYN|ACK: Initial server window 33304 (scale 1), options
[nop,nop,TS,mss
1460,nop,wscale 1,nop,nop,sackOK].
Then we see SYN|ACK retransmitted, ACK retransmitted, etc., until
the server sends a RESET. The TCP handshake never completes. And
someone may already have posted the solution.
For the telnet connection we have a successful handhake.
SYN: Initial client window 65535 (scale 6), same TCP options as
SMTP client. SYN|ACK: Same initial server window and TCP options
as STMP server.
The only difference I see is the initial 1400 client TCP window
size.
As someone already suggested in one of the first follow-ups:
"Would you mind trying to remove "tcp_windowsize = 1400" from
you configuration (do not forget to issue a "postfix reload"
afterwards!)?"
Wietse
Wietse,
Thank you for your patience with me. I tried way too long trying to
resolve this on my own.
I totally forgot that was in main.cf (from months ago trying to resolve
a separate issue and missed it in postconf -n output. (the issue in
question is a networking problem at the provider and the main reason for
the move).
The funny thing is that directive is on the old server as well, which
had no problems connecting to akamai,
At any rate, removing the directive and a reload, postqueue -f resolved
the issue completely.
Again, my thanks.
