sendmail: suddenly not accepting SOME foreign connection

alvinwong · 05-28-2012, 05:32 AM

I got my sendmail messed up.
As far as I remember I haven't set up connection restrictions. When I send a mail from Google or Yahoo to my server it's totally fine.

However when I try to use my home-built postfix server to send, it gets a connection timed out. Trying to `telnet xxxxxxx 25` from my home also gets a connection refused.

I can see that sendmail is listening to all by `netstat -tl` and Google/Yahoo can send mail to it. Frankly my home setup fails. Anyone have any idea?

alvinwong · 05-28-2012, 07:11 AM

`netstat -tlp`:

Code:

Proto Recv-Q Send-Q Local Address               Foreign Address             State       PID/Program name
tcp        0      0 *:smtp                      *:*                         LISTEN      2212/sendmail: acce
(...)

`ls -l /proc/2212|grep exe`:

Code:

lrwxrwxrwx 1 root root  0 2012-05-28 20:06 exe -> /usr/sbin/sendmail.sendmail

So I am sure that sendmail is listening to everyone.

The main problem is that I can't access it at home, under a router, with DHCP.
I tried renewing my ISP's DHCP and still fails.
But for Google/Yahoo and some other SMTP servers can. (I saw it in maillog)