Disable email sync outside working hours Is there any way or a mail app where I can set a (per account) sync time? I would like the app to only fetch mails from my (work) account Mo-Fri 9-5 or if I manually sync.

I use k-9 mail since I got my first Android phone and it has a "quiet time" feature. But this seems somewhat broken in recent Android versions and I would like to have something even more aggressive if possible so I can set the app to not even download new emails from my email account at certain times.

Android version 8 (phone) and 9 (tablet).
FairEmail is a popular open source Email client (crossed 100,000 downloads) which can do this for all accounts (global) but not per account. This is because of maintenance and support of app plus battery consumption.

However, you can still use automation for custom polling to achieve individual account sync (this is a pro feature) 

You can set the day /hour wise schedule



Developer is very active and responsive as you can see from the XDA thread, which is the right place to get your questions answered.

I am an extremely satisfied user of FairEmail and not affiliated anyway with it.