sendmail doesn't like udp protocol being blocked

[monkeyboi]

so i disabled all incoming udp connections from outside my network and sendmail was not too happy about it...
it works again when i enable udp connections from the net..

does sendmail require udp connections from the net to work??? if so what port to they use?

[madcompnerd]

iptables allows ports to be called by name, and I would imagine sendmail is a registered number. Try opening it by sendmail's name.

[bathory]

I think that sendmail uses udp just to communicate with your DNS to resolve host names as a misure to block spam, mail-relays etc. Try to open only udp port 53 to see if it works.

[monkeyboi]

Originally posted by bathory
I think that sendmail uses udp just to communicate with your DNS to resolve host names as a misure to block spam, mail-relays etc. Try to open only udp port 53 to see if it works.

nope still doesn't work!