Very Slow Email Delivery

Discuss your pilot or production implementation with other Zimbra admins or our engineers.
combrolegit
Posts: 19
Joined: Tue Dec 31, 2019 7:42 am

Very Slow Email Delivery

Post by combrolegit »

Hi,

I'm new to this forum so does in Zimbra Server, I installed Zimbra ZCS 8.6 for a year, at the beginning everything seem so good, but recently I'm facing a very slow email delivery (email delivery can takes up to 3 hours to be delivered in/out) and a huge number of mail queue, I've been searching for this kind of issue before through Google, but still no luck to find the answer, I analyze with these command zmqstat and qshape, the result as follows:

active=1723
incoming=12
deferred=69
hold=0
corrupt=0

When I chceck in qshape:

T 5 10 20 40 80 160 320 640 1280 1280+
TOTAL 1603 370 683 250 300 0 0 0 0 0 0
the***.com 958 289 178 221 270 0 0 0 0 0 0
tem***.co.id 574 73 495 6 0 0 0 0 0 0 0
te***anet 26 6 4 10 6 0 0 0 0 0 0
gmail.com 20 2 1 10 7 0 0 0 0 0 0
in****et.co.id 10 0 0 0 10 0 0 0 0 0 0

Well unfortunately the 3 top domain listed is our organization domain and it is legitimate.

Here's my server specs:

VMWare
8 Core Processor
20 GB RAM

1000+ Mailbox

I need help to boost up the email delivery of my Zimbra Server, please guide me to do that, many thanks for you kind understanding and your help guys...
phoenix
Ambassador
Ambassador
Posts: 27272
Joined: Fri Sep 12, 2014 9:56 pm
Location: Liverpool, England

Re: Very Slow Email Delivery

Post by phoenix »

The first thing you should do is upgrade your ZCS version to the latest release, there are exploits/hacks for that version of ZCS and your server may be compromised. There is a thread in this forum about CVE exploits, I'd suggest you read that and see if there's a problem with your server.
Regards

Bill

Rspamd: A high performance spamassassin replacement

Per ardua ad astra
neutronscott
Posts: 28
Joined: Fri Jun 09, 2017 2:05 pm

Re: Very Slow Email Delivery

Post by neutronscott »

I had issue on 8.7.x from a very large IMAP mailbox with multiple connections caused this. Eventually I found in mailbox.log that the messages were not delivered because the IMAP threads had locks on these mailboxes.
It really helped clearing out that mailbox so that many clients were not trying to sync so much, and mail flowed. But in most cases I suspect you'd want to check the following:

Find the reason for defer
grep status=deferred /var/log/zimbra.log
What's the destination and messages generally seen here?

Check some things in https://wiki.zimbra.com/wiki/Performanc ... eployments
zmprov gs `zmhostname` zimbraLmtpNumThreads zimbraImapMaxConnections zimbraImapNumThreads
zmlocalconfig | grep nio
combrolegit
Posts: 19
Joined: Tue Dec 31, 2019 7:42 am

Re: Very Slow Email Delivery

Post by combrolegit »

phoenix wrote:The first thing you should do is upgrade your ZCS version to the latest release, there are exploits/hacks for that version of ZCS and your server may be compromised. There is a thread in this forum about CVE exploits, I'd suggest you read that and see if there's a problem with your server.
Hi, thank you for your reply, before upgrading, may I ask some? first which is the best method for upgrading, in-place upgrade(is it possible?) or build a new server? and the second one how much is maximum mailbox for ZCS single sever deployment?(mine is 1000+, is it too much?), anyway I've been searching for in-place upgrade guide due to limitation to build a new server but still not find the best complete guidance for this.
combrolegit
Posts: 19
Joined: Tue Dec 31, 2019 7:42 am

Re: Very Slow Email Delivery

Post by combrolegit »

Well, most of deferred email caused by over quota issue...and I often decide just to clean up, anyway is there any way to set bounce directly if the recipient mailbox is full so it will not go to deferred queue?
neutronscott wrote:I had issue on 8.7.x from a very large IMAP mailbox with multiple connections caused this. Eventually I found in mailbox.log that the messages were not delivered because the IMAP threads had locks on these mailboxes.
It really helped clearing out that mailbox so that many clients were not trying to sync so much, and mail flowed. But in most cases I suspect you'd want to check the following:

Find the reason for defer
grep status=deferred /var/log/zimbra.log
What's the destination and messages generally seen here?

Check some things in https://wiki.zimbra.com/wiki/Performanc ... eployments
zmprov gs `zmhostname` zimbraLmtpNumThreads zimbraImapMaxConnections zimbraImapNumThreads
zmlocalconfig | grep nio
neutronscott
Posts: 28
Joined: Fri Jun 09, 2017 2:05 pm

Re: Very Slow Email Delivery

Post by neutronscott »

combrolegit wrote:Well, most of deferred email caused by over quota issue...and I often decide just to clean up, anyway is there any way to set bounce directly if the recipient mailbox is full so it will not go to deferred queue?
This seems to be only option to perm fail it at the mailbox server. That means the MTA still accepts and they get a bounce but it won't be in your queue
https://wiki.zimbra.com/wiki/Controllin ... box_-_LMTP
combrolegit
Posts: 19
Joined: Tue Dec 31, 2019 7:42 am

Re: Very Slow Email Delivery

Post by combrolegit »

neutronscott wrote:
combrolegit wrote:Well, most of deferred email caused by over quota issue...and I often decide just to clean up, anyway is there any way to set bounce directly if the recipient mailbox is full so it will not go to deferred queue?
This seems to be only option to perm fail it at the mailbox server. That means the MTA still accepts and they get a bounce but it won't be in your queue
https://wiki.zimbra.com/wiki/Controllin ... box_-_LMTP
Hi, thank you neutronscott! that seems to solved my issue so far, overide the default value of queue and quota configuration is the key answer of it, I change the queue lifetime from 5d to 15m, then set TRUE value to zmprov mcf zimbraLmtpPermanentFailureWhenOverQuota, many thanks for your guidance.
combrolegit
Posts: 19
Joined: Tue Dec 31, 2019 7:42 am

Re: Very Slow Email Delivery

Post by combrolegit »

neutronscott wrote:
combrolegit wrote:Well, most of deferred email caused by over quota issue...and I often decide just to clean up, anyway is there any way to set bounce directly if the recipient mailbox is full so it will not go to deferred queue?
This seems to be only option to perm fail it at the mailbox server. That means the MTA still accepts and they get a bounce but it won't be in your queue
https://wiki.zimbra.com/wiki/Controllin ... box_-_LMTP
Hi, well...the problem occcuring again, hmmmh...still got no clue until now, here's the qshape:
Capture.PNG
Capture.PNG (4.43 KiB) Viewed 5726 times
combrolegit
Posts: 19
Joined: Tue Dec 31, 2019 7:42 am

Re: Very Slow Email Delivery

Post by combrolegit »

I've upgraded the Ubuntu to 18.04.3 version also the ZCS to 8.8.15, but the problem still occurring, the current server even bigger RAM size at 32 G, I really need your help to fix this guys,thank you, here's the current situation:
Capture.PNG
Capture.PNG (4.43 KiB) Viewed 5725 times
User avatar
zimico
Outstanding Member
Outstanding Member
Posts: 225
Joined: Mon Nov 14, 2016 8:03 am
Location: Vietnam
ZCS/ZD Version: 8.8.15 P3
Contact:

Re: Very Slow Email Delivery

Post by zimico »

Hi,
You have to confirm that your server is not compromised before using inplace upgrade.
And if your server is ok, please see: https://wiki.zimbra.com/wiki/Spamming_troubleshooting
Regards,
Minh.
Post Reply