Hi, sorry, I know this is not directly related to postfix but I know that there are several very experienced people reading this list. My question is how you (the people that use and administer mailservers) handle the localpart case sensivity according to rfc5321:
"The local-part of a mailbox MUST BE treated as case sensitive." Background ist the development of postfwd rate limiting, which allows amongst others to place maximum values (count or volume) for sender or recipient addresses. To do so postfwd creates a hash with the given address as index. At the moment it is easy to "trick" such limits by varying the case of the addresses, meaning that postfwd will create different counters for bob@alice.local, BoB@alice.local and bob@AlicE.local. No question - with future versions postfwd will definitely treat the domainpart case-insensitive, so that bob@alice.local and bob@AlicE.local will have the same counter. But for the localpart I see two options, wondering which I should choose: 1.) Being strictly rfc5321 compliant: By default postfwd creates two different counters for bob@alice.local and BoB@alice.local. To change this the admin has to specify --non-rfc5321-rate-case-sensivity (or s.th. similar). 2.) Being real-world compliant: By default postfwd uses the same counter for bob@alice.local and BoB@alice.local. To change this the admin has to specify --strict-rfc5321-rate-case-sensivity. What's your opinion on that? Do you know any real-world systems that distinguish between bob@alice.local and BoB@alice.local (means that both point to different mailboxes). Thank you in advance Jan