WHY IS THE SECOND EMAIL ADDRESS I HAVE OPN MY IPHONE ONLY KEEPING A SMALL AMOUNT OF EMAILS. OLDER ONES DROP OFF ONCE NEW ONES ARRIVE?

If your incoming email messages are automatically removed, the primary cause could be misconfigured rule/filter

To resolve this issue, please make sure you haven't created any rules/filters with the action to Delete / Move it that would affect the email messages being moved automatically to another folder.

1. Is this your corporate iPhone? Then please contact the system administrator of your corporate
2. If it is your personal device, in that case, do you have any profile installed by your corporate/organisation/enterprise/School Management?
   1. Erase the profile added by you If you have installed a profile on your own --> Install or remove configuration profiles on iPhone - Apple ...
   2. Or please contact the system administrator of the organisation who provided the profile to you