Does anybody know how to exclude the ".nomedia"-file in folder "parts" from being deleted by this shell command?
find /storage/emulated/0/Android/data/org.kman.AquaMail/files/parts/ -type f -mtime +6 ! -name ".nomedia" -exec rm {} \;
If you want it to be case insensitive (i.e. for both .nomedia and .NOMEDIA):
find /storage/emulated/0/Android/data/org.kman.AquaMail/files/parts/ -type f -mtime +6 ! -iname ".nomedia" -exec rm {} \;
(Some versions of 'find' allow "-not" instead of "!", but "!" should be robust.)