Monday, July 29, 2002 06:37 AM
Maybe it is taking "foo" as the localpart, assuming your local domain will be added by the local mail system e.g. it will be turned into "firstname.lastname@example.org" (equivalently, taking "foobar.com" and assuming it will be turned into "email@example.com").
The local MTA (e.g. Sendmail or whatever) can be configured to accept bare localparts (e.g. "foo") in rfc822 address headers (e.g. "From:", "Reply-To:", "To:", "Cc:", "Bcc:"), and assume it will be constructing the rfc821 envelope addresses from them (e.g. the "MAIL FROM" and "RCPT TO" and DSN's) and that consequently it should append the local domain to them (e.g. "firstname.lastname@example.org"). Or (better) it can be configured to require domains on addresses, in which case it (the local MTA) will reject the message submission.