Mail slow in Outlook on large account

[wheez]

I have been trying to solve this for some time, but I struggled to do so, maybe there is something I am overlooking.

One of my users is having a bad experience using Outlook as a Mail client. The inbox is about 7~8 GB in size. It's the Mac Version of Outlook.

Currently, Outlook is connected via SMTP server. The Problem is that the search is very slow with about 10–20 seconds and the attachments can not be downloaded.
I have tested it on my machine, and it is the same problem with a completely newly installed Outlook.
I have tested the same Account with Thunderbird and search and attachments work without a Problem. Same with the SoGo webmail client.

I have given mail 3GB of Memory and enabled Full Text Search (Solr) as well.

But for me, it seemed like an Outlook specific problem, since I could not recreate the Issue with Thunderbird. The user would like to continue to use it since they have their workflow in it and other mails as well.

I have done more research and discovered active sync which seems to be specifically for Outlook:
https://forum.cloudron.io/topic/8153/activesync

After enabling it I found out that the Mac client does not support ActiveSync, only in the beta version.
After enabling the Beta version Outlook tells me that the version of ActiveSync is not supported.

Now I have no more Ideas on how to proceed. Is there a plan to update the ActiveSync on SoGo? Or is that an upstream Issue?

Do you have any other ideas to improve the Performance of Outlook via the SMTP?

Any leads or help is appreciated!
Thank you!

[fbartels]

Hi @wheez,

I have given mail 3GB of Memory and enabled Full Text Search (Solr) as well.

Quite often mail desktop clients don't perform searches on the server, but instead are using a local index for this. Outlook for windows and thunderbird are doing so. https://superuser.com/questions/1771275/outlook-in-macos-search-issue suggests this may also be the case for the Mac version of outlook. In general I see a lot of messages about slow search in Outlook on the Mac.

Mac client does not support ActiveSync, only in the beta version

That must be a misunderstanding. The beta version if the new Mac Outlook has gained support to talk with Exchange in February this year. But I doubt that Microsoft would use ActiveSync for this.

[michaelpope]

@wheez Heya Wheez,

A few questions.

1. Are they using the new version of Outlook that proxies everything through Microsoft's servers? Or traditional Outlook that does things directly (don't know how to check this myself, you'll have to look it up).
2. Are they connecting to the Cloudron Mail server using IMAP or POP (I don't think ActiveSync would be supported - but Outlook can do IMAP and POP just fine).
3. Try removing and then re-adding the mail account in Outlook. How long does it take to download all the mail? Do the same in Thunderbird. Is it a similar time (should be pretty short for 7-8 GB of mail)? Also how long does it take? (If it takes longer than about 5 minutes to download the mail in Thunderbird, your server provider may be throttling IMAP or POP some).
4. Apparently, Outlook's search on Mac has a lot of issues : https://apple.stackexchange.com/questions/354269/how-to-fix-outlook-for-mac-search

[wheez]

Thank you both for your replies/help!
I have done some research and had some success.

When I connect directly to the IMAP server, not proxying through Microsoft servers, then the performance is fine. It is not the fastest (super slow compared to thunderbird) but definitely usable.

I also managed to get Microsoft Exchange support on Outlook for mac. It is true that it is out of beta, but only in the Outlook you download from microsoft.com directly. The Outlook in the Mac App Store does not support Exchange yet.

Now my problem is, that I want to use Exchange so that Calendars are also synced into Outlook. It seems like CalDav is not supported by Outlook, so I was hoping that exchange would work. Whenever I try to connect to the SoGo Webmail client via Outlook with Exchange selected I get this error in the SoGO logs:

Jul 31 19:18:57 2024/07/31 17:18:57 [error] 29#29: *366 open() "/usr/local/lib/GNUstep/SOGo/WebServerResources/EWS/Exchange.asmx" failed (2: No such file or directory), client: 172.18.0.1, server: webmail.DOMAIN, request: "GET /EWS/Exchange.asmx HTTP/1.1", host: "webmail.DOMAIN"
Jul 31 19:18:57 172.18.0.1 - - [31/Jul/2024:17:18:57 +0000] "GET /EWS/Exchange.asmx HTTP/1.1" 404 134 "-" "MacOutlook/16.87.24071426 (Intelx64 Mac OS X 14.4.1 (Build 23E224))"

Outlook only tells me login not possible.

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When I want to test the server with https://testconnectivity.microsoft.com/ I am getting the following error:

https://webmail.DOMAIN/Microsoft-Server-ActiveSync/ -> Error 401

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Is this an error I am able to fix or is Exchange not supported but only ActiveSync? I am still unsure if it is the same or not.

Thank you for your help!

[fbartels]

EWS and EAS are just two of the many protocols of Outlook and Sogo only implements EAS.

Side note:

open() "/usr/local/lib/GNUstep/SOGo/WebServerResources/EWS/Exchange.asmx" failed (2: No such file or directory)

Does sogo really try to execute everything that you throw at their webserver. That does not sound like a good idea.

[wheez]

Thank you that made me understand the differences quite well.

Sadly it seems like the issue is not resolved yet though. The Outlook client seems to stay slow. It was just shortly working a bit better it seems.

What I don't understand is the following though:
Only the modern Mac Outlook is slow/buggy. If I switch to legacy outlook there are no Problems.
Thunderbird is having no Problems as well, same with other clients.

I found out though that when I enable Offline Mode in the modern Outlook Mac client, then the search is not slow anymore. Still there is the problem that Attachments are buggy and when you try to open them Outlook says that they have to be redownloaded to open them (which does not work).

The modern Outlook for Mac does work with other IMAP clients though. So It's not Purely an Outlook problem and not Purely a Cloudron Mail problem. There just seems to be a problem in the communication between them.

I just seem to no be able to debug it. Does anyone have an idea what it could be?