On Thu, 28 Oct 2021 at 07:40, Bernardo Reino <reinob@bbmk.org> wrote:
[...]
Further to the responses you have received already, I'd like to note that if you want to receive mail at {alias}@{user}.mydomain.com then, at the time of *sending* the e-mail there needs to be an MX record for user, as otherwise the sender won't be able to connect to your (postfix) server.
That means that the users will have to exist *before* postfix receives the message, and thus clearly before dovecot receives it.. so you may have to reconsider your requirement of adding users of on-the-fly.
Excellent point. So we are also using a DNS server with this (CoreDNS with some custom plugins). This means we are able to handle the dynamic MX records (plus also allowing us to expire domains if we need to).
Cheers,
Felix