Hello Andreas and welcome to the Eight Forums,
First of all, thank you for this great tutorial.
Thank you.
Andreas did you read post 3 yet please? Your profile still shows your on Windows 8 ? ..Is that true?
Post 3 reminds members to Please give all the needed OS info on your posts that asks questions, so Please first give us complete information in your post so that I can know what information to point you to in the Tutorial, thank you.
FWIW, no matter what though, the WinMail "Compact" and all those Advanced settings are 100% working on Every version of Windows now, providing you applied the directions properly for whatever version of Windows that you really have. (it sounds like you don't have the right msoe.dll (and it's corresponding reg update) for your OS version will cause that exact problem - it's all there, it's for you to place it correctly) ..but again, what version of Windows are you using dictates what post attachments and bit to use?
I tried to set a different number than 100.
When I went back to the same dialog, the number was set to 100 again.
100 is actually a good setting, I always have mine @ 99 and both give a good safety factor to stave off MSC which I won't get into here. Even though the setting goes up to max 999 but these higher numbers can be very problematic!
Anyway, After you set your desired number, and click Close on that box, now here on the Advanced tab box still open ..on its bottom right side -
Did you click the "Apply" button? ..because if not, then your choice Will Not take, and revert!
Does anyone know the registry key where the number is saved?
Yes that particular registry key location is:
HKEY_CURRENT_USER\Software\Microsoft\Windows Mail
..and it's about the 5th one down under
"Compact Check Count"
However since the Tutorial gives you everything to work properly "if you have the right files/reg placed" ..then that is really the only Proper way to do it! ..So you should fix what you have astray please since other stuff must not be working right either ...unless, it's simply that you forgot to click the Apply button to have it actually take hold which you would certainly Not be the first person to make that simple mistake either; if not that though then most likely your msoe.dll versions (or its applicable reg) are incorrect and will cause your exact issue too! Let us know how you make out.