18 Sep
2003
18 Sep
'03
12:36 a.m.
On Thu, 18 Sep 2003 00:25:48 -0400 (EDT) Gerald <gcoon@inch.com> wrote: <snip>
...and for heavens sake, stop accepting any kind of request at all on port 25!! Just shut it down altogether. There is no reason for you to accept any connection of any kind on port 25!
I shall only respond to this portion. The rest of it ... well, I'll just leave it at that :) If they don't accept anything on port 25, either by sending all packets to /dev/null or by responding with SYN+RST ("Connection refused"), MTAs everywhere will consider this a "temporary error." In other words, the mail will sit on queues for weeks, typically, until an error is finally sent to the sender. Currently an error is sent to the sender immediately.