Interface freezing and synchronization delays during high background resource usage

1

Hi everyone,

I’ve been using eM Client as my primary mail client for a while now, and I generally love the smooth UI, but I’ve recently run into a performance hurdle that I’m hoping to get some insight on.

I’ve noticed that whenever my local environment is under significant resource pressure—specifically when I’m running several background automation scripts or testing the arceus xexecutor environment for its multi-threading capabilities—eM Client starts to exhibit some strange behavior. The most noticeable issue is that the application interface “hangs” momentarily when I’m switching between folders or trying to compose a new message. Additionally, I’ve had several instances where my IMAP synchronization hits a “Socket Timeout” error even though my internet connection is stable.

While I was discussing these environmental bottlenecks with some other developers, it seemed like the system’s main thread was being deprioritized, causing the database operations in eM Client to lag behind. Has anyone else noticed their mail client becoming “sluggish” or hitting silent sync failures if there are other high-performance tasks running in the background? I’m seeing occasional “Request timed out” messages in the Operations window during these resource spikes.

I’m trying to figure out if there’s a way to make the application more resilient—perhaps by adjusting the sync frequency or tweaking the local database maintenance settings to ensure the UI remains fluid in “noisy” multitasking environments. If you’ve dealt with stabilizing the desktop experience while multitasking heavily, I’d really value your advice!

Best regards!

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No i personally don’t experience that issue using the latest eM Client 10.4.5326 on Windows 11 (25H2) or Mac OS26 (26.4.1) with an eg: i7 cpu & m1 cpu with 16gb ram & m2 ssd drives on a 50mbps nbn connection.

So if you have good spec computer and are running the latest eM Client version with one of the latest OS versions, then could be “possibly something running resident in the background” interferring causing the timeouts. Or could be something going on with the internet speed.

Programs such as eg: optionally installed firewall / security programs, or optionally installed antivirus programs or vpns can sometimes interfere with Mail clients. So if you have anything like that installed “other than what comes default with your OS”, try completely disabling those to test.

Apart from that “test your internet connection speed when you are running high-performance tasks in the background” to make sure its not an internet issue delaying or running slow at that time. As could be your internet connection “is busy with other app activity” causing timeouts.

Also if you are using Wifi connection to your router “and there is others accessing the Wifi router at the same time” and they are uploading or downloading, that can sometimes affect Mail clients getting timeouts depending on the spec of the router. eg: Some of the latest Wifi 6e routers on 5ghz have better bandwidth and lower latency to each device which can make a difference if there is other users.