[Dovecot] LMTP returncode 450?

[Peter Mogensen]

On 2011-06-28 01:58, Timo Sirainen wrote:
> On Mon, 2011-06-27 at 14:55 +0200, Peter Mogensen wrote:
>
>> How do I get the LMTP-server to know which mailbox's are locally hosted
>> and return SMTP code 450 if delivery is attempted to a non local user?
>
> You can't, at least that way. Why are you trying to deliver mails to a
> non-local mailbox? You could anyway use Dovecot as LMTP proxy to the
> remote LMTP server and it would deliver the mail there without an error.

I was wondering if I could skip running a Postfix or other MTA along 
with dovecot and just let mail be delivered directly to the final host 
by LMTP.
It's no problem to have Postfix do a virtual_mailbox_domains lookup 
before handing it to local LMTP, but it would be simpler with only Dovecot.

>> I can see that a lookup in the userdb is done, but now matter what I
>> return (1/111) from my checkpassword script I just get:
>
> Set lmtp_proxy=yes and have passdb lookup return proxy=y and
> host=1.2.3.4.

But how does the LMTP proxy deal with temporary errors? It has no queue 
like the SMTP-server ?

/Peter