Sendmail doesn't work with iptables, even though smtp and dns are allowed

view full story

http://serverfault.com – I have sendmail installed on Ubuntu 10.04 solely for the use of the php mail() function. This works fine unless iptables is running (I've been using "sendmail [email protected]" to test this). I think that I have allowed SMTP and DNS (the script I am using to test iptables rules is below, in my version are the actual IPs of my hosts nameservers), but to no avail! iptables --flush iptables -A INPUT -p tcp --dport 22 -j ACCEPT iptables -A INPUT -p tcp --dport 80 -j ACCEPT iptables -A INPUT -p tcp --dport 443 -j ACCEPT Postgres iptables -A INPUT -p tcp --dport 5432 -j ACCEPT Webmi (HowTos)