iPhone mail suddenly downloaded thousands of old mail!

Sadly - it didn't - it just downloads the NEXT bunch of 250-500 emails chronologically - I have these going back to 2013! Just on one account. sigh…..

It appears that it wants me to run through the entire historical downloading of every email and then delete them, and on and on. Interestingly it recognizes the ones I have already deleted and starts the next download of 500 on the previous date where it left off.

It is basically acting as an iPhone would if you created a new mail account and its downloading all "unread" emails (it thinks you haven't seen yet) off the server.

I'll try and delete the smallest (newest) account and recreate it and see what happens

I'm not sure what you mean - I think you are confusing IMAP with POP. IMAP settings is what will make your emails delete from the server in sync with your device or mail account from your computer etc. POP will treat each entity separately so if you delete or file on one device it will NOT mimic that behavior on the server.

I keep all my emails as POP and never removed from the server because I manage many crucial accounts for myself and other people, including critical businesses, so this way I can check an email from home and delete it but its still gonna be in the mail when I get to work, and it will still be on the server in case everyone deleted it from their mail and desperately needs to find it (whether financial or legal.)

Periodically I will go into the servers and manually move and/or delete and clean up email to free up server space. One of the most annoying changes to the iOS a few incarnations ago was the removal of the choice in mail to only download the last 50 emails for each account. Now when you add an email account (say to a new iPhone) down comes zillions of emails from the POP server. sigh….

UPDATE - This theoretically "Fixed" it for me for the moment (going to each server and moving all mail from the inboxes to a new folder called iPhone fiasco), but I don't know that's really a fix.

I have no idea what caused the iPhone to do this, and it can't be the servers, because they are all different on different hosts, and some that are corporations like embark/centurylink or gmail. It is definitely an iPhone issue.

Even when I delete emails, it still shows hundreds of emails in the red badge count and in the overall "inbox" on the iPhone even though when you look at the inboxes of individual accounts they are empty. When you trash emails, they appear to be gone from the inbox, but the count remains in the red badge and the overall "inbox"….. then after a while the trash will "download" a count of what I deleted. Meaning: the phone seems to have an enormous amount of time recognizing that emails have been moved from the inbox to the trash and then recognizing they have been deleted - many times putting the emails BACK into the inbox ⚠ If the overall inbox shows a count of emails, when you look, they are ghosted light grey in color, have crazy impossible dates (like 1969 or 2000) and say "no content" - but they remain in the inbox count.

For the record, I do not open weird emails or attachments so I can't imagine this is a virus - no idea where that would come from magically, since I was doing NOTHING with the phone all day - it sits on my desk waiting for me to leave! LOL!!!!!

I've never had any problem with my iPhones and this one is only 2 months old running the newest iOS. So weird!!!!!!!

I hope this helps someone else…..

Thank you all for helping me!