Heureka, it seems we have a breakthrough. We’ve found a workaround for that issue and it is included in this version:
https://www.emclient.com/dist/v10.3.1720_Mac/setup.pkg
Can you please try it and confirm it really resolves the issue?
It was super hard to find it, but by disabling an undocumented cache in webkit the macOS 15.4 bug/crash seems to be bypassed. It works for us, hopefully it will work for you too.
giving it a shot…fingers crossed ! thanks
This is really great news. I’ll definitely give it a go. Thank you!
I’ve been using v10.1 on my desktop (macOS 15.4; not 15.4.1 yet) today and, several hours in, it still seems to be working fine. I’ve tried to crash the app by opening messages in a new window (double-clicking on messages) and, even though I’ve tried 20 times or more, I’ve not been able to get it to crash. I’ve also tried clicking through the Mail, Calendar, Contacts, Attachments, etc. options in the left hand panel and I’ve tried the Contact Details, Agenda, Invites, and Calendar in the Sidebar on the right. None of this has crashed the app. I then also tried collapsing/expanding the left and right hand panels, perhaps about 10 times each, but no problems here either. So far, I’ve not been able to get v10.1 under macOS 15.4 to crash! 
With your new release, I’ll install this on my laptop with the post-Postbox eM Client 10.3 setup, which has been somewhat “quarantined” since the stability issues arose. I’ll do some testing there and let you know what I find…
The update is now officially released. Based on our tests it resolves the macOS 15.4 issue. We’ll be closely watching whether Apple will finally resolve the bug.
So far 1.5 days of no crashes! I am very optimistic since it was crashing hourly or more prior to the update. Fingers crossed I can keep using em client and not have to go back to Outlook !
This is a completely different topic. This topic is about application crashes. Your problem seems to be is connected to internet connection stability, network issues or a server deliberately closing the connection. Please open a different topic with that.
Hi Michal, to keep you informed:
Using 10.1.4828 under macOS 15.4, I’ve still not had a crash.
I updated my laptop to 10.3.1720.0 under macOS 15.4.1 last week and, with medium usage, I’ve not yet had a crash! Here’s hoping this means the team has indeed found a workaround for now. Thank you very much for everyone’s efforts and for working hard to find a rapid solution while awaiting Apple’s bug fix! 
Mine is crashing constantly since the last update. Multiple times per day.
It’s always in the background, but often I go back to the app and it’s just a spinning beach ball, which i’ve not seen on my Mac for a few years. It’s synced to 2 regular gmail accounts, and two 365 accounts.
Is reverting to the previous build possible? Any tips?
MacBook Pro M2 / MacOS Sonoma 14.7.2 / eM Client 10.3.1720 (b574c3b)
Hi Rexx, it’s possible this would be a new crash, can you send us the crash log?
Close eM Client
Run eM Client from Terminal: press (Cmd+Space) and type (copy) in
“/Applications/eM Client.app/Contents/MacOS/eM Client”
Hit enter and wait for the app to crash / or do the actions you know will crash it
A detailed log should appear in the Terminal after eM Client crashes again so just copy the log and send it to [email protected]
If you want to try a previous update until we can find a fix, all versions can be found in our release history: Release History | eM Client
Thanks. Running now via terminal.
BTW your command needed “quotes” as per below as it wasn’t working with the spaces between eM and Client. Figured out via google tho. I’ll report back!
/Applications/“eM Client.app”/Contents/MacOS/“eM Client”
