> On Jan 31, 2018, at 9:53 AM, Stephen Satchell <l...@satchell.net> wrote:
>
> Can you characterize the distribution of your mail delivery? In other words,
> if you take each mailpiece, determine the MX, and collate the results, do you
> have a lot of mail going to relatively few endpoints, or do you have a wide
> spread of targets?
The OP's original message said:
> I have single mail server that send relatively large amounts of emails at
> least 3 times a day ranging from 15K to 50K each time ..
>
> 80% of emails are going to one domain owned by my company (Domain1).. The
> current mail flow does around 1K-1.2K per minute , this is CentOS 7 VM ( 4
> CPU/8GB Memory) running on SSD Datastore.
With slow delivery to this one domain. To figure out why, requires a
quantitative approach to the problem, but the OP has not yet measured
the delivery latency or determined whether the delay is in connection
setup (before HELO) or in message delivery (MAIL FROM to DOT).
Postfix records these in the "delays=" field of each delivery log entry.
The OP must also attempt to understand whether the destination is
actually capable of processing email any faster.
DNS issues seem unlikely given that raising concurrency does not
dramatically improve throughput. This does not mean that DNS
problems (especially with reverse resolution) might not be a
contributing factor. So it would be a good idea to make sure
that the receiving system is able to reverse resolve the IP
address of the sending system, and is not configured to tarpit
or otherwise slow down input as a misplaced anti-spam feature.
--
Viktor.
