On Wed, Jan 19, 2011 at 03:19:41PM -0500, Manuel Mely wrote:
> > Your relay host is violating the SMTP protocol by prematurely closing
> > the connection, and on top of that without even responding with a 5XX
> > error for the problem recipient (which Postfix would otherwise "remove"
> > from the queued list of recipients, and then succeed with the remaining
> > recipients when the message is retried).
>
> Right! The thing is that i have some scripts to check my
> internal SMTP servers availability. Then, if they don't have connection with
> my relay node, i have to put a 4xx code to stop growing my queue from remote
> servers in internet. but i missed that 421 closes transmission and for
> multiple recipients this is not good.
If you are going to tempfail *all* recipients from the SMTP client in
question, then 421 is impolite, but OK. If you want to accept some
recipients, but not others, 421 is a bad idea.
> Is it better to set smtp_destination_recipient_limit = 1 or change my 421
> code to something like 450 or 5xx? if my client SMTP server is down, i
> don't want to accept messages to their users from internet, just defer those
> messages in the remote server queue.
I am confused about who's the server and who's the client, which server
is returning 421 and dropping the connection, ...
You need to explain the context more clearly. Perhaps even an ASCII-art
diagram to indicate who's doing what...
--
Viktor.
