Thus said "Constantine A. Murenin" on Thu, 03 Mar 2016 15:09:46 -0600:
> > The MTA will decide who will get foo-bar@. > > How? A /dev/mind RPC? :-) Because the MTA is configured to handle it? :-) > And what happens if a "conflicting" user gets created after a mail was > sent, but before it was delivered? "This behaviour is undefined"? I'm not exactly sure what you mean by conflicting... The MTA, again, will already be configured to deal with addresses and mapping them to users. And the behavior is not undefined. If an email address exists and the MTA knows about the email address it will get delivered if the username configured to receive it exists. If the MTA knows about it, but the OS doesn't know about it, the MTA will queue it up until the local user who is supposed to receive it is created. If the username exists and the MTA doesn't have an email address for it, the email will bounce. My MTA can handle both + and - for email addresses and can map email addresses to local users in any fashion that the OS supports. For example, let's assume I have a local user named foo and I have assigned an email address foo@ and I have configured that email address to accept wildcard extensions (e.g. foo-*@ gets delivered to username test). Then, I create a local user named foo-bar. Clearly now, I cannot give the local username foo-bar an email address of foo-bar@ because, well, that is already superceded by test's wildcard claim on the address. Assuming that I had to give the user that username, what email address could I give him? Anything I want, as long as it is not part of foo-*@ I have the following mapping which permits username foo to receive email for foo@, foo-*@, and foo+*@, and another mapping which permits username foo-bar to receive email for foo_bar@ and foo_bar-*@: =foo:foo:1004:1004:/home/foo:-:: +foo-:foo:1004:1004:/home/foo:-:: +foo+:foo:1004:1004:/home/foo:-:: =foo_bar:foo-bar:1003:1003:/home/foo-bar:-:: +foo_bar:foo-bar:1003:1003:/home/foo-bar:-:: Is this sensible to do? Who knows, but the point is, just because - exists in usernames doesn't necessarily mean that it shouldn't be used in email extensions. Must there be a one-to-one mapping between email addresses and local usernames? In many systems it is typical for the email address to not even remotely resemble a local username. Thanks, Andy -- TAI64 timestamp: 4000000056d912b2
