Originally Posted by
revelations
You dont have to, I have seen cases where the email provider has on their end and fucked things up for clients (eg. shaw, telus).
You still have not mentioned who the email provider is. - edit gmail? did I see that right? You are using POP with a gmail account?
If its gmail, it can act strange on its own. I have seen it disable 'less secure' features that I specifically disabled for functionality.
Try getting a GMAIL app for the phone - this can often fix issues with clients and their settings not working with googles back end connection and security.