To make my mail server SPF compliant, I have it do SRS-rewriting of all
outgoing envelope-from addresses, using the method described at
http://srs-socketmap.info/sendmailsrs.htm . In my capacity as server
admin, possible messages to the domain used for SRS go to me.
Yesterday I received a "spam challenge" message from one of those
challenge/response filter services, which let me know that the
[SRS-signed address] address was not whitelisted. The "spam challenge"
message was sent to the rewritten envelope-from address, not to the
The incident made me realize that having all outgoing envelope-from
addresses rewritten clashes with the challenge/response approach. Not
that I personally care much about the latter, but some users may
consider it a problem.
Anybody who knows of a simple solution to this problem?
Other related comments?