Help! I linked 2 of my additional emails to my Gmail and now my account has gone crazy. I do not have a good understanding of how server forwarding works, so I just googled it and followed the directions online. I followed the instructions to link accounts using account forwarding. One of them is through Pop3, and the other one is through Gmailify. I also attempted to add a third through yahoo, but yahoo requires a pro membership to set up IMAP email forwarding.
Now, 5 hours later, things have gone crazy. Every 10 seconds my unread email count goes up, despite me not seeing any new emails in any of my accounts. The total space used by my account has gone up by 4%. I now have triple copies of all my email folders. I tried unlinking and relinking an account earlier, and I am unclear if that made the problem worse. I had an enormous amount of unread emails before in my original account, could that be causing the problem? I don't understand where all of these extra emails are, and where they are taking up so much space. What do I do? What have I done?
In addition to this, my phone has now seemed to go nuts also. When I opened my email, my phone downloaded 1000's of old emails. Emails from 2015 now show up right beneath other emails of mine (all from the same account). My phone is rapidly filling up!
I am guessing the problem lies in my lack of understanding about how email servers work. Since this happened, I have done some research about IMAP and POP and things like that. I think I have a basic understanding of how this works. I also think this person - https://discussions.apple.com/thread/7481256 - may have had a similar problem. I have no idea how to fix all this however. I'm on a Mac using 10.12.6, and the problem is appearing across multiple browsers and devices.
EDIT: The rate of new unread emails has slowed down significantly, as of a few hours later. I would still like to understand what is happening.
Thanks in advance!