Outlook and IMAP very Slow

Discussion forum for Enterprise Edition.
dcol
Posts: 237
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol »

Interesting someone with so much Exchange experience saying Outlook is crap. I agree which is why I am not supporting it anymore with my users.
I also have been in IT a long time, since 1977 and started as a hardware design engineer with Wang Labs.

dcol
Posts: 237
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol »

Repeated comments
Last edited by dcol on Fri Sep 25, 2020 5:14 pm, edited 1 time in total.

dcol
Posts: 237
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol »

Repeated comments

dcol
Posts: 237
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol »

Not supporting Outlook has become a problem for some of my users. The issue has become worse and Outlook is slower than ever before. Some users have 250K emails in their mailbox and for these users Outlook has become unusable. I do not have XLIST enabled. Switching users to MAPI has also not worked well with performance. It is faster initially, but eventually comes to a crawl.

Is there a way to stop syncing of already read emails in Outlook? Seems that is the issue. Outlook syncs all the time. It is as though ME is telling Outlook it has to resync all email everytime an email is sent or received. Maybe the user has mobile Outlook and it is asking for resync. Does seem as though this issue started when users started using mobile Outlook on their Android phones about a year or two ago.

MailEnable-Ian
Site Admin
Posts: 9738
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Outlook and IMAP very Slow

Post by MailEnable-Ian »

Hi,

Outlook will always try to sync all folders in the mailbox along with all the data. Have you looked into creating send/receive groups in the Windows Outlook clients to see if this helps?

Please see: https://support.microsoft.com/en-us/office/change-send-receive-group-settings-7184f59d-c194-44d7-973a-7af568a918d0

As for the mobile devices we would need to inspect the relevant IMAP log files to see what the client is doing at the time. You will need to submit a support ticket so that you can forward the relevant log files.
Regards,

Ian Margarone
MailEnable Support

dcol
Posts: 237
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol »

The problem arose when users upgraded Office to newer versions. Starting with Outlook 2013, MS no longer supports 'Download Headers Only' in IMAP. So what is happening is all the emails and their contents keeps getting reloaded and I know why. I have a script that reindexes all the mailboxes on a periodic scheduled basis. Don't remember why I had to do this right now, but this is causing everything to be reloaded over and over. I think I did this to recover missing emails. A lot of the emails are huge and there are a lot of them.

MailEnable-Ian
Site Admin
Posts: 9738
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Outlook and IMAP very Slow

Post by MailEnable-Ian »

Hi,

You might want to update your script and not delete indexes as this will only make the sync issues worse. If you need to add messages back into folders for many mailboxes then you are better placing _change.dty files in the folders to update the index.

Please see: http://www.mailenable.com/kb/content/article.asp?ID=ME020652
Regards,

Ian Margarone
MailEnable Support

dcol
Posts: 237
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol »

That is the commands in the script using _change.dty. When that forced update happens, all the emails are reindexed.

I dug in and now I see why I have that script. I have users move spam email to a spam folder and nightly I auto-train the dictionary then clean up those folders by copying _change.dty and deleting the index.xml in those folders which are subfolders in the Index folder. That causes a total resync in Outlook. But I am only touching a couple users and others are affected.
Last edited by dcol on Wed Oct 27, 2021 11:09 pm, edited 1 time in total.

MailEnable-Ian
Site Admin
Posts: 9738
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Outlook and IMAP very Slow

Post by MailEnable-Ian »

Hi,

It will reindex but the client will not download the messages it has already downloaded to the client. The only way the client would reindex the folder is if the creation date of the index.xml is changed.
Regards,

Ian Margarone
MailEnable Support

dcol
Posts: 237
Joined: Fri May 26, 2017 11:25 pm

Re: Outlook and IMAP very Slow

Post by dcol »

So you are saying to not delete the index.xml, just add the _change.dty and it will just update the changes (deletions and additions)

MailEnable-Ian
Site Admin
Posts: 9738
Joined: Mon Mar 22, 2004 4:44 am
Location: Melbourne, Victoria, Australia

Re: Outlook and IMAP very Slow

Post by MailEnable-Ian »

Hi,

Correct
Regards,

Ian Margarone
MailEnable Support

Post Reply