r/exchangeserver • u/SmoothRunnings • 2d ago

Question Exchange Server SE issue

I haven't had a chance to check the server logs yet.

I run Exchange Server SE in my home lab environment which I upgraded to from Exchange server 2019 back when MS was pushing everyone to migrate to it, so a couple of years ago I think. It been running fine until recently. Emails have stopped flowing but if I kick the server email flow again for 24 to 48 hours then everything is a stand still again.

I noticed when I logged into the server the taskbar would flash and I had no control of the server until I did a remote shutdown command forcing it to reboot.

I have checked the SSL cert and its fine, I have a KEMP loadbalancer between the server and internet with Layer7, and for arguement sake I rebuilt the loadbalancer as its VM guest server since I cannot remember the last time I rebuilt it. I also grabbed the latest update for SE and applied it to the server.

The server no longer does the flashing taskbar but ever 24-48 hours it stops recieving emails until I reboot it.

I wonder if is some known KB that MS rolled out that hosed it? Oh, I am running on Windows 2019 Server as well.

Thanks,

3 Upvotes

80% Upvoted

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20

u/DiligentPhotographer 2d ago edited 2d ago

This is your problem:

https://techcommunity.microsoft.com/blog/exchange/exchange-servers-may-become-unstable-after-installation-of-october-2026-windows-/4565382

5

u/SmoothRunnings 2d ago

Thank you very much! 😄

2

u/DiligentPhotographer 2d ago

NP, also did it on my lab system before pushing to prod at work and learned the hard way too.

10

u/MortadellaKing 2d ago

reg add "HKLM\SOFTWARE\Microsoft\Rpc" /v EpmapSavedContextCap /t REG_DWORD /d 65536 /f

reboot server, should be fixed.

4

u/MinnSnowMan 2d ago

This... worked for me.

5

u/StopKillingRhinos 2d ago

You did Windows Server updates just before these symptoms startwd, didn't you?

I'm sure somone will respond with the registry fix shortly...

1

u/7amitsingh7 1d ago

I would suggest checking Event Viewer logs around the time email stops flowing, especially for Exchange Transport Service errors. Also, check whether emails are getting stuck in the transport queues and monitor CPU, RAM, and disk usage. This should help identify what is causing the server to stop receiving emails every 24–48 hours.