Alessio Cecchi:
> Hi,
>
> I switched a postfix setup from delivery email via dovecot-lda to dovecot
> LMTP.
>
> But now I found an issue, when an email address has a spike of
> received emails in a short time postfix try to deliver too many
> messages for this mailbox in parallel, on dovecot side we see
> deliveries go slow only for this mailbox, all lmtp processes are
> busy for this mailbox and delivery for others users stay in queue
> or are very slow.
>
> I'm also investigating on dovecot side, but in the meantime I would
> like to set postfix for delivery a less number of parallel message
> for the same mailbox.
If your master.cf has an entry like this:
lmtp .. .. .. .. .. .. lmtp
then configure main.cf thusly:
lmtp_destination_recipient_limit=1
lmtp_destination_concurrency_limit=2
And do "postfix reload".
The first setting changes the meaning of _destination_concurrency_limit
from concurrency per domain, to concurrency per recipient.
The second setting allows no more than two concurrent deliveries
to the same recipient.
This is indentoial to the default settings for local UNIX-style
mailbox delivery:
local_destination_recipient_limit = 1
local_destination_concurrency_limit = 2
The purpose of these settings the same as what you want: to avoid
lots of deliveries to the same recipient.
Wietse
