On a new setup, I get this as part of a bounce message when trying to send mail from the webmail, does anyone know what I'd need to do or where I'd need to start to fix this?
(error message follows
<firstname.lastname@example.org>: host oncall-pc.com[220.127.116.11] said:
550-Verification failed for <email@example.com> 550-The
mail server could not deliver mail to firstname.lastname@example.org
The account or domain may not exist, they may be blacklisted, or missing
the proper dns entries. 550 Sender verify failed (in reply to RCPT TO