iPhone Mail

Recently my iPhone 6S keeps telling me "unable to remove mail" every time I try to delete selected items. Tried soft start and re start etc to reboot iPhone but still won't delete.

What kind of a mail account do you have? POP? IMAP?

No idea. They are Yahoo and Gmail accounts.

It looks like it's a GMail problem as the yahoo emails don't come back to my inbox.

It sounds like your Gmail is an IMAP account which is why it still shows the mail from the server. I had the same problem with my Gmail account when it was both IMAP and POP. I cancelled the IMAP portion and use Gmail POP only. Problems resolved. My iCloud account remains as IMAP which is OK but does give me duplicate mail from certain places.

Ok thanks for the help with trying to sort it out.