Setup the number of SMTP Processes

[pc-nico]

Hello Guys

i have seach but not found or i am blind...

where can i set the number of allowed smtp processes?
I have set it in master.cf but i think it didn´t use by zimbra.

(background: the server is very busy, but smtp clients must wait for a free connect
Zimbra Server very slow - Too many SMTP connections)

[mmorse]

By "but smtp clients must wait for a free connect" it sounds like you want that higher?
How much mail is this server typically trafficking in? I would focus on preventing these unwanted connections from staying open so long rather than just upping the limit.

Default is 100 but if you do need to adjust it:
su - zimbra
postconf -e default_process_limit=x
postfix reload

Just be aware that more processes does not always equal more speed, if local delivery is disk limited adding more processes will just consume memory but won't actually speed things up.

Plus if your process limit is too high, you start to invite a cascade effect, where you run out of some other resource (CPU or disk throughput) and each process takes so long that it times out. I think the idea is to set the process limit high enough that you don't hit it in every day use but low enough that it triggers before the machine overloads.

You could play with adjusting your in_flow_delay to 0 (just for a tiny bit, default is 1s) and see what happens as a test.
Of course do make sure things are in-check by decent concurrency limits.

Postfix Performance Tuning

Originally Posted by pc-nico

the master problem was, that anybody starts a Spam Attack and using our info@ - E-Mailaddress as sender.
This cause that over 1600 mails come in between a little time.

So you are receiving lots of mail TO the info@domain.com account/dist list? ie:Normal receiving, but just sheer volume of spam mail to it.
Have you locked the info@domain.com address so that only allowed people could send to it?: RestrictPostfixRecipients - Zimbra :: Wiki

I don't think you're saying this, but just to cover the other angle:
By "anybody starts a Spam Attack and using our info@ - E-Mailaddress as sender" are you saying that lots of mail is going out from your box with a forged info@ as the FROM? ie: Someone got a-hold of authentication or trusted networks is a little to wide...

[tiarra]

how can i find the no.of smtp connections made in zimbra.
Thanks in advance

[uxbod]

As mmorse has said the default is 100.

[veronica]

In any case of you think these are valid mails thn i would recommend scaling system by adding a MTA and a Mailstore.

[tiarra]

CAn i fidn how many smtp,pop conections made from any logs?

[uxbod]

You would have to parse /opt/zimbra/log/audit.log ... What are you trying to achieve ? if you want to see how many connections are open at any one time you could do

lsof -ni 4tcp:25 -i4tcp:110