Error undefined index: company in customer.php

I get this error when registering a new customer. And this only happened when I enabled the Mail Server configurations. If I removed all of the mail configurations, the error won't show up but the site can't send an email.

"Notice: Undefined index: company in /home/project/catalog/model/account/customer.php on line 64Warning: Cannot modify header information - headers already sent by..."

Any solution to this?

Thank you