Fourhundred Thecat:
> Hello,
>
> I have suddenly started seeing following messages in my logs:
>
> timeout after END-OF-MESSAGE from a9-244.smtp-out.amazonses.com
>
> Full context here: https://ctxt.io/2/AABgbxFEFQ
>
> These errors are coming from completely unrelated clients. Are suddenly
> all clients on the internet misconfigured? I did not change anything on
> my side.
Not in Postfix, but perhaps something was changed in the network stack.
> I can provide more examples if necesary.
2022-04-09 09:27:31 postfix:25/smtpd: disconnect from
o196.p31.mailjet.com[185.211.122.196] ehlo=2 starttls=1 mail=1 rcpt=1 data=1
commands=6
2022-04-09 10:09:45 postfix:25/smtpd: disconnect from
a9-244.smtp-out.amazonses.com[54.240.9.244] ehlo=2 starttls=1 mail=1 rcpt=1
data=1 commands=6
Note that Postfix received no QUIT command.
Possible scenarios:
1) The client did not send QUIT and kept the connection open for
more than 20s. This is unlikely if it is a sudden change that affects
connections from many different clients.
2) The client did send QUIT and did close the connection, but some
overly aggressive NAT/packet filter dropped TCP connection state
when it saw that the client wants to close the connection. Since
this is a sudden change that affects connections from many different
clients, it is more likly to be on your end of the network.
Wietse
