Take the 2-minute tour ×  When I send an email to a non-existent
domain, or a domain without an mx record, I am receiving the
email at my domain for the same user. To clarify my issue,
here's an example:  from the command line I send an email
/usr/sbin/sendmail info@thisdomaindoesntexist.com this is my
message  After doing this, I find an email to
info@www.mydomain.com (where www.mydomain.com is the domain name
of the server from which I sent the email). In the headers of
the email, I see that originally the To: address was
info@thisdomaindoesntexist.com, but then the server changed it
to info@www.mydomain.com.  Ideally, I want the mail server to
discard this message or bounce it, not relay it to my domain.
I've been playing around with the sendmail config
(/etc/mail/sendmail.mc) for hours, but I am still having no luck
with figuring out why this is happening. Is this even sendmail
that's doing it, or am I looking in the wrong place?  Thanks in
advance.  share|improve this question It is sendmail that's doi