Wietse Venema:
> Patrick Westenberg:
> > Hello,
> >
> > I'd like to know if there are any plans to enable LMTP with the
> > smtpd_proxy_filter?
>
> An SMTP-to-LMTP adapter is fundamentally not possible. With N
> recipients, LMTP gives N end-of-data replies (*), while SMTP gives
> one.
>
> (*) For example, the LMTP server has delivered one recipient and
> has not delivered another recipient.
The before-filter SMTP server could reply with 4XX to the second,
third, etc. recipient of multi-recipient mail, and force the remote
SMTP client to deliver one multi-recipient message as multiple
single-recipient messages. That would, however, defeat the purpose
of using LMTP instead of SMTP for the smtpd_proxy_filter interface.
Wietse
> An LMTP-to-SMTP adapter is trivial. With N recipients, simply repeat
> the one SMTP end-of-data reply N times.
>
> Wietse
>
