On 20 Oct 2020, at 19:01, Viktor Dukhovni <postfix-us...@dukhovni.org> wrote:
> On Tue, Oct 20, 2020 at 05:29:22PM -0600, @lbutlr wrote:
>
>>>> The current setup uses recipient_bcc_maps which I would have thought
>>>> did what I wanted, but it actually does all outbound mail as well.
>>>
>>> With recipient_bcc_maps, the specified BCC recipient from the RHS of the
>>> table is added whenever the message envelope contains a recipient that
>>> matches the LHS of the table. Therefore, either the outbound mail in
>>> question also had local recipients, or your table inadvertently matches
>>> some or all remote recipients.
>>
>> Right, which means custom m matches for every domain instead of being
>> able to just catch the local users.
>
> No, it just means that the table should not match remote recipients, how
> that is done depends on the table type.
>
>>> I don't see anything above that limits the matched recipients to local
>>> users. Do you? What is the intent of the "([^.]*)" pattern following
>>> the "@" sign? It will always match, possibly an empty string if the
>>> first character after "@" is ".", but otherwise some initial substring
>>> of the domain part.
>>
>> The first character cannot be a . in an email address
>> (u...@.example.com is invalid), so it matches the first portions of
>> the domain part of the email address. So 'example' in example.com or
>> 'mail' in mail.example.com.
>
> Lossy, but if you just want the first label, so be it. What is your
> definition of a "local" recipient? Do you literally mean a mailbox
> handled via local(8), aliases(5) and delivery to a unix-account, or do
> you mean anything you're willing to accept inbound?
These are the same thing in my case, I only accept mail for accounts that will
deliver to a local (well, virtual in the context of postfix) user, though
u...@example.com may actually deliver to us...@someotherexample.tld.
> If you're abusing terminology and really "local" as in local address
> class,
No, sorry, I was using 'local' as in 'local to the mail server' and not 'local
as in a shell user on $mydomain', apologies. All users are virtual users on
virtual domains (even me and where root mail is aliased), but local to the mail
server.
>> I'm fine with that. I have no quoted local part emails and if anyone
>> created one with a double .. (an obviously attempt to break things)
>> I'd deal with that with a clue bat.
>
> I don't recommend waiting for broken edge-cases to show in practice, but
> your system your rules...
Every user is known to me, and only a very few users can create new email
accounts. Everyone can create aliases, but nearly none know how to.
> Otherwise, the simplest solution is to completely separate
> inbound and outbound mail either with multiple instances,
> or just separate smtpd(8) and cleanup(8) instances.
That is probably the way to go. I am also looking at the possibility of using a
default.sieve in dovecot since at that point we've already reached the LDA and
the outbound mail cannot be affected. The script I have to generate the postfix
configuration file can do much the same for default sieve, and it would take
all of this out of postfix.
> Then your recipient bcc table would never see the outbound
> mail in the first place.
Yeah.
The more I think about this, the more I think default.sieve is the way to go.
The reason that I did not do this before was because the mail server used to
discard high scoring mail that had been expected and I had the backup to
recover even those mails, but the mail server now rejects high scoring mail
before it is accepted.
I have a suspicion I am forgetting something, though.
Thank you, again, for your time.
--
'They say that whoever pays the piper calls the tune.' 'But,
gentlemen,' said Mr Saveloy, 'whoever holds a knife to the
piper's throat writes the symphony.' --Interesting Times
