A cloud-based server set-up by a 3rd party is using sendmail to do email sending.
Now, the sendmail has been configured so that emails from
www-data@localhost  is sent as
firstname.lastname@example.org. The emails mostly are sent to the 3rd party email, for example
email@example.com (notice different target domain).
However, now we need to also send email to
firstname.lastname@example.org. Attempting to do that, however, results in
550 5.1.1 <email@example.com>... User unknown.
I'm severely in the blank for configuring sendmail.
Can anyone provide some pointers on how to do this properly?
 That is the
ServerAdmin name as defined in
"the sendmail has been configured so that emails from www-data@localhost is sent as firstname.lastname@example.org". How, exactly?
I think through the following lines in
dnl # Replace sender's domain MASQUERADE_AS(`example.com')dnl FEATURE(masquerade_envelope)dnl FEATURE(masquerade_entire_domain)dnl MASQUERADE_DOMAIN(`example.com')dnl
(Again, I'm not the one making the sendmail.mc file; if there's a certain line to look for, I'd be happy to post it here).
Here are additional info:
root@webserver:/etc/mail# grep '^Fw' sendmail.cf Fw/etc/mail/local-host-names %[^\#] root@webserver:/etc/mail# cat local-host-names localhost webserver