dovecot - Jul 2011 - Lots of LMTP errors Remote server not answering (DATA output timeout) (in reply to end of DATA command))

Hello,

	I have configured two dovecot servers with director acting as 
lmtp/imap/pop proxy server with 8 dovecot backend servers.

	In our test environment we had no problem, but when we migrated to 
production environment, our mail list server (it delivers mail through 
lmtp) is having a lot of errors like this:

451 4.4.0 Remote server not answering (DATA output timeout) (in reply to 
end of DATA command))

	Proxy and backend servers are not loaded.

	Any idea?


-- 
Angel L. Mateo Mart?nez
Secci?n de Telem?tica
?rea de Tecnolog?as de la Informaci?n       _o)
y las Comunicaciones Aplicadas (ATICA)      / \\
http://www.um.es/atica                    _(___V
Tfo: 868887590
Fax: 868888337

El 08/07/11 12:18, Angel L. Mateo escribi?:
> Hello,
>
> I have configured two dovecot servers with director acting as
> lmtp/imap/pop proxy server with 8 dovecot backend servers.
>
> In our test environment we had no problem, but when we migrated to
> production environment, our mail list server (it delivers mail through
> lmtp) is having a lot of errors like this:
>
> 451 4.4.0 Remote server not answering (DATA output timeout) (in reply to
> end of DATA command))
>
> Proxy and backend servers are not loaded.
>
> Any idea?
>
	By now, I think I have resolved the problem. We have limited the rate 
at what list server delivers mail to dovecot. The default postfix 
configuration is:

lmtp_destination_concurrency_limit = 20
lmtp_destination_recipient_limit = 50

that is,

	a maximum of 20 lmtp concurrence connections with a maximum of 50 
recipients per connection. We have decrease to 5 and 10 and since then 
we have no more data output timeout errors.


-- 
Angel L. Mateo Mart?nez
Secci?n de Telem?tica
?rea de Tecnolog?as de la Informaci?n       _o)
y las Comunicaciones Aplicadas (ATICA)      / \\
http://www.um.es/atica                    _(___V
Tfo: 868887590
Fax: 868888337