I keep receiving returned mail messages like this one:
This message was created automatically by mail delivery software.
A message that you sent could not be delivered to one or more of its
recipients. This is a permanent error. The following address(es) failed:
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 ***
as if I was trying to send an email from my registered mail account to email@example.com
What's happening ?? I can't figure it out