I am trying to send an email from gmail, and other web email accounts and I am getting the following bounce back error messages: What is causing this because I know the email addresses are correct that I am sending to?
Mail Delivery Subsystem <email@example.com> to me
show details 8:05 pm (22 minutes ago)
This is an automatically generated Delivery Status Notification
Delivery to the following recipient failed permanently:
Technical details of permanent failure:
PERM_FAILURE: SMTP Error (state 13): 550 <firstname.lastname@example.org>: Recipient address rejected: No such user (email@example.com)