Bug in Android 10 on Samsung S10

Ihave a Samsung S10 running Android 10.Earlier O/S versions on Samsung had a manual set up for Email accounts that had a button “Leave on Server” when setting up POP instead of IMAP which does not have a “leave on server’ option which is vital to me and I suspect many others.
If you receive an email with 5 pages of Xl attached one cannot work on it on the phone so return to a PC to edit and possibly forward. The problem is in an attempt to keep the phone in box clean and you delete it from the phone it deletes fro the Email server . Samsung say talk to Google/Android which is effectively impossible.
Any suggestions on how to get this bug fixed?