It's very easy to block the windows updates

Please now tell me how to prevent the Windows 10 Mail from auto-starting during bootup. And I do also get many conflicts with automatic updates which cause a reboot.

I never saw Windows 10 mail in my very uptodate version of Windows 10 pro.
I still use Windows Live Mail or webmail.
Sorry I can't help you with this.

Once a month a make a return point and switch Windows Update on.
I can see which updates there are and let them install.

Afterwards I test the most used programs and if something goes wrong I use my return point. Since the beginning of Windows 10 this works very good for me.
 

Blocking windows 10 updates is not what I am after, I am always happy to update if improves windows and/or adds new features. That being said there are different versions of windows around, the pro version has (or used to have) more possibilities to postpone /block upgrades I vaguely recall. Windows 10 Home users may be more "locked down". Using a return point is one way for sure. 

To cornico: I also prefer windows live mail.  I see that you have a Dutch OS, I live in Belgian and although being Flemish and native Dutch speaking, I prefer to use this language forum. English in tools and IT is just more handy (and I assume more people on the forums). The only annoying thing about these windows updates is that I have win 10 pro N (albeit in English 😃) which means I have to download media feature pack for N (Europe) to get back the windows media player after each update due to this retarded European anti-monopoly laws.