sendmail outgoing to internet domain
 

hi

i have sendmail installed in my home machine and also dns is configured and also i have configured mx for mail server. my dns is unregistered and my question is that can i send mail to external account like yahoo or gmail to check whether my is working or not.

Sure you can.
Just keep in mind, that it might end to the spam folder in gmail, or yahoo, or even rejeced, if the IP of your mailserver does not resolve to a hostname. So watch /var/log/maillog to see what happens.

Regards