Interesting. Have you looked at this? https://serverfault.com/questions/133190/host-wildcard-subdomains-using-postfix
[People have too much "flair" and rep points and I can't participate in those stackexchange discussions or ask or answer like I used to.] On October 27, 2021 3:15:01 PM AKDT, dove...@ptld.com wrote: >> I think your approach would work, however, if I set >> up aliases similar to: >> >> @barbaz.mydomain.com -> bar...@mydomain.com. >> >> I believe I can do that in postfix with some regex magic. > >Yes, that would work perfectly without any regex. >You just point the catchall alias to the "user". >@barbaz.mydomain.com -> bar...@mydomain.com > > > >> one stumbling block could be that we don't >> know the various subdomains ahead of time. >> >> The subdomain can be any value that the user >> wants, and we don't want them to have to >> precreate them before they can use an address > >Best to my knowledge this is not possible with postfix. But ask the >postfix mailing list to get a definitive answer. In postfix you have to >tell it the domains it accepts mail for, anything else it considers >relaying. Otherwise how does postfix know that email is meant to be >saved here or it is just passing through and you want postfix to query >DNS to find out where it goes (if relaying is even allowed). > > > >> The purpose of the system is that users can create disposable/temporary >> email addresses for various testing jobs. > >Are you aware of postfix recipient_delimiter? It allows for disposable / >wild card addresses. If enabled in postfix, you setup a mailbox user >like bar...@mydomain.com and any address with that user and the >delimiter would still get delivered to that user. > > bar...@mydomain.com -> bar...@mydomain.com > barbaz+randomt...@mydomain.com -> bar...@mydomain.com > barbaz+te...@mydomain.com -> bar...@mydomain.com > >You can change the + to any symbol you want postfix to look out for. > > > >> I think my "creating users" was me wanting to make sure that when >> postfix >> passes an email for "bar...@mydomain.com" to Dovecot, then Dovecot will >> store it and wait for >> someone to come along and impersonate barbaz. i.e. "barbaz" doesn't >> have to exist as a user >> already before Dovecot will store the mail. > >If you are using LMTP dovecot will only accept emails from postfix that >it can lookup the /directory/path to from one of the userdb{} or >passdb{} sections. If dovecot can not find a match in any of the >userdb{} or passdb{} it will reject the email as user unknown causing >postfix to send a undeliverable notice email back to the envelope sender >address, also known as back-scatter. I am not aware of a way to use >wildcard addresses in dovecot userdb{}, i don't think its possible but i >don't know what i don't know. -- Sent from my Android device with K-9 Mail. Please excuse my brevity.