Suspicious Gmail Issues -- Possible for ex boyfriend to interfere with emails?

So I'm almost certain (for a variety of reasons) that a guy I was seeing at one point had hacked my phone (he's a senior software engineer at a major tech company).I think he may have interfered with my ability to send and receive emails from another guy--we'll call this guy Billy. In one of my gmail accounts when I hover over Billy's email icon it reads ":mo" where his name would go above his email address, and in my other email account it reads ":ke" where his name would go above his email address. Billy's email address is the same in both of my accounts. I added Billy to my contacts to see if these weird letters appear there, and on both accounts the name fields are empty.Is it possible that my ex blocked my ability to reply to Billy's email address on one of these accounts? What explains the ":mo" vs ":ke" difference? Is there anyway I can fix this? I really like Billy and want to make sure that he is getting my emails (the way he has responded in person would make it seem like he hasn't been)---if there is an issue, is there anyway I can fix this?Any insight into this would be much appreciated! via /r/tech https://ift.tt/2I4hrvZ