On Sun, 16 Apr 2006, Jeremy Harris wrote: [...] > - reject senders not matching the specific auth data
"Rejection" is not as easy as it sounds. We try to reject mail submissions which present non-existent sender addresses - but mail client software typically does not react well to a 5xx telling it that the client's purportd sender address is invalid. We've seen quite a number of different scenarios in which the client station then continues to batter the mail server with repeated attempts to send the mail, more or less indefinitely until the mail admin steps in. We could hardly accept the submission and then try to report the error back by means of a "bounce", since the bounce is *supposed* to go to the envelope sender address, and the whole problem is that the envelope sender is invalid! In our case, that's specifically a problem for mail submission from trusted IP addresses, for which we don't yet enforce authentication. If and when the submission policy is changed to demand authentication from all senders, then presumably the solution to an invalid sender address from the client, is to replace the invalid address with the canonical sender address of the authenticated user. Or at least to report rejection by means of a bounce /to/ the canonical address of the authenticated sender...? regards -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
