Every time one of my email addresses doesn't work on my mail app, due to wrong password or whatever, it deletes all of the contacts form my phone. What can I do to stop this from happening?

Every time one of my email addresses doesn't work on my mail app, due to wrong password or whatever, it deletes all of the contacts form my phone. What can I do to stop this from happening?

I have tried deleting the account and it deletes all my contacts. I have verizon and even using back up assistant, it says the contacts are there but they aren't. The only way i can find a contact is if I start to type a name in and new text but once i sent the new text, the name disappears and it just shows the number. Siri nor the address book don't recognize any contacts at all.