Mail Disappears off iPad after I access my mail on Mac
I have a MacPro desktop, iPad, and iPhone, all tied together, all running the most recent updates. Recently, my iPad was acting up and not retrieving my mail on my main account. The other devices were (and continue to be) just fine. I deleted that mail account off my iPad, then added it back in. Email began behaving and getting delivered just like always EXCEPT if I then check email on my MacPro. Once I do that, all inbox email associated with my main account, both read and unread COMPLETELY disappears off my iPad. Even if the message is flagged, it is gone. Everything stays put on the Mac and the iPhone until I delete it or otherwise.
I searched these communities and thus far have tried shutting down all background apps, restarting (multiple times) and changed the delete messages setting to "never", which really should only matter to trashed messages, not those sitting in my inbox.
I checked the "server port" on my phone and compared it to the one on my iPad. They were different, so I put them both on the same one as the iPhone. The message showed up on the Mac and on the iPad, but as soon as I refreshed the mail (such as to update), **POOF** the message in my inbox was gone on the iPad.
I would be most appreciative if someone could offer me insight as to why this occurs and how I can fix it. Likely it is some squirrelly setting I haven't discovered yet, but I am hoping one of you geniuses out there can set me straight!
Thank you in advance~