I run Postfix 3.3.
My inbound mail is working great, except for a few 'newsletters' I sign up for.
>From a few "legit" newsletter senders, i.e. those that I opt-in with, I get
CONNECT/DISCONNECT
pairs in my logs. And of course no delivery.
In the logs I get these
Jul 23 06:22:21 maryland postfix/handoff/smtpd[7668]: connect from
smtp10.ymem.net[24.73.102.76]
Jul 23 06:22:22 maryland postfix/handoff/smtpd[7668]: disconnect from
smtp10.ymem.net[24.73.102.76] ehlo=1 mail=0/1 quit=1 commands=2/3
On the postfix mailing list I found this thread
http://postfix.1071664.n5.nabble.com/meaning-of-connect-immediately-followed-by-disconnect-in-mail-log-td32773.html
that says
As of 20090109, Postfix 2.6 supports a workaround.
...
Specify "tcp_windowsize = 65535" (or less) to work around routerswith
broken TCP window scaling implementations.
So I did that and have
postconf tcp_windowsize
tcp_windowsize = 65535
But I still get these connect/disconnect pairs.
Any other ideas for workaround?
I added "-v" for the 'handoff/smtpd' instance but that doesn't seem to tell me
what's causing these immediate disconnects. Is there a better way to get more
information on the disconnect reason?
Rob
