Outlook and IMAP very Slow

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MartynK
Posts: 1364
Joined: Sat Dec 28, 2002 1:12 am
Location: Hong Kong

Outlook and IMAP very Slow

Post by MartynK » Mon Jul 13, 2020 1:42 am

It seems that my Outlook/IMAP setup has gone on a go slow.

When I first startup Outlook, it updates the inbox quickly, then starts updating subscribed folders which seems to never end.

This in turn then stops any updates coming in or going out of the inbox for instance.

If I click on another folder, it can take an age if at all to update.

I have deleted and recreated my Outlook profile, also tried this on a number of PCs, same result.

The mailbox is 10gb, so I gave it 24 hours to update, which it did, but back to the same slowness after.

Any ideas ?

MartynK
Posts: 1364
Joined: Sat Dec 28, 2002 1:12 am
Location: Hong Kong

Re: Outlook and IMAP very Slow

Post by MartynK » Mon Jul 13, 2020 3:58 am

So an update, I have downloaded Thunderbird and that seems to be working OK.

Even while its doing its initial sync, it still sends and receives to inbox.

So looks like something specific to Outlook, not sure where to go now.

Mailenable, any ideas ?

MailEnable-Ian
Site Admin
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Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Outlook and IMAP very Slow

Post by MailEnable-Ian » Tue Jul 14, 2020 12:16 am

Hi Martyn,

What version of Enterprise are you running?
Regards,

Ian Margarone
MailEnable Support

MartynK
Posts: 1364
Joined: Sat Dec 28, 2002 1:12 am
Location: Hong Kong

Re: Outlook and IMAP very Slow

Post by MartynK » Tue Jul 14, 2020 1:27 am

hi

The latest v10.30

dcol
Posts: 103
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol » Wed Sep 09, 2020 3:54 pm

Same issue here running Enterprise 10.31
IMAP and Outlook is very slow with synchronization on large mailboxes. Even on local network accounts.

Any hints on tweaks or settings. I did increase the Worker Thread Pool Size to 100. No change.

MartynK
Posts: 1364
Joined: Sat Dec 28, 2002 1:12 am
Location: Hong Kong

Re: Outlook and IMAP very Slow

Post by MartynK » Thu Sep 10, 2020 2:04 am

I dont know, not got to the bottom of it yet, its a background task I am affraid.

What I have done over various times, removed all AV, run with various AVs and settings.

This does only seem to be an issue with large mailboxes (which I have always had).

My server is 6 cores and 16gb memory, loads of disk space, so no issues there.

Latency to the server I thought could make a big difference, but as you said, its the same locally, I have not tested that yet.

dcol
Posts: 103
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol » Thu Sep 10, 2020 2:44 am

I tried switching to MAPI and saw a big improvment. So there is definetly an IMAP issie with large mailboxes. I don,t have Premium so I am limited to 20 MAPI connection. Really need a resolution to this issue

dcol
Posts: 103
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol » Mon Sep 21, 2020 9:34 pm

Have to backtrack on that last post. MAPI is also slow. Thunderbird is quick and works as expected as does webmail, but Outlook is very slow. Just sent an email in Outlook and it was in the outbox for 2 minutes before it got sent out. What's going on?
My ME version is 10.31 and Outlook is 2016.

Another point to make. This all started after I moved ME to another server last month. The new server is using Windows Server 2019 and is a much faster system. But maybe there was a tweak or setting I applied a long time ago in the old server. Any help is appreciated.

MartynK
Posts: 1364
Joined: Sat Dec 28, 2002 1:12 am
Location: Hong Kong

Re: Outlook and IMAP very Slow

Post by MartynK » Tue Sep 22, 2020 4:14 am

Now that is interesting, I moved to a Windows 2019 server around the same time as my issues started.

At the same time my latency increased a lot (30ms to over 120ms), but as I have seen, that does not seem to be an issue with both Thunderbird and Outlook with small mailboxes.

When I migrated Mailenable to the new server, I exported the whole setup including all registry settings, so basically nothing on that side has changed in the past months other than upgrading to newer Mailenable versions.

I have taken a copy of my Mailenable server and my large mailbox and put both on VMs, configured Outlook from scratch and everything worked fine.

I have ruled out AV causing the problems as I have the same issues with ESET and Bitdefender as I do without any AV installed.

So all I have remaining now to be the problem is big mailboxes (and I mean total size, all folders and emails, not just the Inbox as mine has few emails) and latency affecting how things work. Maybe something to do with the way Outlook talks to the server, that I am unsure at the moment.

dcol
Posts: 103
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol » Tue Sep 22, 2020 3:14 pm

Common item here seems to be Server 2019 which is suppose to be faster than 2016. Maybe Outlook is looking for Exchange because of something Server 2019 responds to? Just grasping at this point. And you are correct, large mailboxes are MUCH slower than small ones. Why is that? The only reasonable answer is constant syncing. Outlook is so busy trying to sync 10K+ emails, it gets bogged down. Maybe whatever ME tells outlook to not sync already synced email, is not working.
Come on ME peeps, look into this. I will be forced to move to another email server at renewal time if you don't fix this.

MartynK
Posts: 1364
Joined: Sat Dec 28, 2002 1:12 am
Location: Hong Kong

Re: Outlook and IMAP very Slow

Post by MartynK » Wed Sep 23, 2020 2:55 am

Yes, the common bit here may be 2019, but as I said, I took a copy of a 6gb mailbox and setup a full test.

Server:
Server 2019, 4 Cores, 8gb memory and 100gb Disk
MailEnable 10.31 Enterprise
Microsoft Defender AV enabled.

Client:
Windows 10 Pro, 4 Cores, 8gb memory and 100gb Disk
Outlook from Office 365 install
Microsoft Defender AV enabled.

All systems and software fully patched with everything I could find.

I configured Outlook using IMAP, no SSL as I did not have a Cert on the server.

It did take a long time to sync the initial mailbox down to the client, but I would expect that as its a large mailbox with 1000's of emails and 100's of folders.

Once the initial sync was complete, flipping back and forth between folders seems to be OK.

The next thing I need to do is create another VM with a test account so I can send email back and forth so that changes happen on my client.

dcol
Posts: 103
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol » Wed Sep 23, 2020 3:19 pm

I just took the easy approach and told all users to switch to Thunderbird and import from Outlook. I don't have the time to deal with this issue anymore.
Thunderbird supports CardDAV/CalDAV and address books. The newest version, 78, has everything my users require and is very fast even with huge mailboxes.

Just use TB. Mailenable is obviously not 100% compatible with Outlook IMAP, SMTP, or MAPI. Whether it is MS or ME's fault. I don't care and it seems ME doesn't either.
I will be taking my ME renewal money when due and invest in a more Outlook compatible mail server. One with better support. Proof being the lack of ME's response to this and most other forum threads.

MartynK
Posts: 1364
Joined: Sat Dec 28, 2002 1:12 am
Location: Hong Kong

Re: Outlook and IMAP very Slow

Post by MartynK » Thu Sep 24, 2020 1:19 am

In Mailenable's defense here, have you raised a support call ?

I have been working with them via a support call and they have been very hard working with me on the issue.

Remember this is a public forum, its not here for you to get "one to one" support for every issue.

To flip this around, what have Microsoft said, have you logged a call with them ?

What do your Outlook log files show when your accessing large mailboxes ?

dcol
Posts: 103
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol » Thu Sep 24, 2020 3:30 pm

Not paying for ME or MS support to fix their issue. It's ME who should be on a support call with MS, not me. Not an issue anymore since everyone is willing to switch to TB or webmail. Problem solved. Besides, I am not the one with issues, remote users are. So next to impossible to debug on a support call. I have personally never liked Outlook and use TB. Logs showed nothing out of the ordinary.

I know the issue is with Outlook, it is a horrible program. Always have been. It was written to work with Exchange, so MS is not interested in small email servers. I am sure their support answer would be it's ME's problem. Been there with useless MS support. And don't get me started on Exchange Server. I have worked as a network support specialist for 15 years and spent 50% of my time every day on Exchange related issues.

MartynK
Posts: 1364
Joined: Sat Dec 28, 2002 1:12 am
Location: Hong Kong

Re: Outlook and IMAP very Slow

Post by MartynK » Fri Sep 25, 2020 2:39 am

You may be surprised how good ME support is and if it is their problem, I am sure they wont be charging you. I have been using MailEnable personally since 2002 and I will still say its the best Windows mail server going and some of the best support.

Yes, Outlook is crap, but IMAP is a pretty standard protocol and it does seem to work, so something is clogging the system up somewhere.
Just throwing everyone over to TB may be your solution, but it has not fixed the underlying problem.

Unfortunately I am just in to my 36th year in IT, started with MS DOS v1 back in 1984 (migrating from CPM), was a beta tester for MS Exchange before its initial release in 96 and up until last year I worked heavily with it, now given up that side of my job.

Well if you happy with your solution then not a lot else to say.

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