I have a customer using the old legacy free Google Suite accounts - firstly he seems to be able to have upto 100 accounts which is weird since I thought it was limited to 5 but anyways..  Hes using Outlook 2016 and connecting to it via POP.  He also has it on his iphone setup as a normal gmail account as far as I know.  Hes receiving all the emails on his phone without any issues but its skipping quite a few on Outlook all of a sudden.  Its been perfectly fine for years up until a few weeks ago.  I decided reset his email settings in outlook, reset the pop connection in gmail so it wouldnt download a crapload of old emails and whilst its working its still skipping quite a few. 

It seems to mainly skip ones that come in overnight yet they are still unread on his phone and on the gmail app.  

Anyone got any suggestions?  I was thinking I could make a new profile and just set it up using imap.  I doubt at this point he'll be willing to pay the $6US/mo since he has around 10 accounts.