email not being sent

[Rick Eicher II]

I am getting the following in the apache logs:

	Error running invoice event ($cust_bill->send();): (customer # 3) can't
send invoice email 	for rick at pbol.net to server localhost! at
/usr/local/lib/perl5/site_perl/5.6.1/FS/cust_main.pm line 1141.

I have set the smtp server to localhost. And a ps aux show that sendmail is
running. Is there something I am not setting?

Also once I do get email to run is there a way to get all customers bill at
one time with one command?

Thanks,
Rick