Am I over reacting?

I have been with my partner for quite some time now and during our relationship we have been very open about our ex's, she is still friends with a few of them which I'm fine with however there is one ex of hers whom she stated she was very annoyed at and didn't want anything to do with him, this was said to me at the beginning of our relationship, over the course of our time together he has made attempts to contact her, some being rude some attention seeking and some being 'nice'. My partner tells me about all the contact she has and she pretty much tells him where to go, I might add that she told me not to speak with my ex as any type of contact with an ex who still holds feelings is good contact in their eyes, anyway recently she has been speaking to him on a more regular basis and the messages are pleasant in content, but I'm confused as to how this ex whom she wanted nothing to do with has now become a regular person to talk too, how should I take this?? I know they have a history but the way I see it is his 'nice' emails are just his way of trying to get back in her good books yet I see no reason for him to be in any 'books' seen as he upset her so much and she wanted nothing to do with him when their relationship ended, what should I do???

Don't go through this relationship with your eyes closed. Keep one leg in and one leg out. This doesn't seem right but then again it could be harmless. Just keep your eyes open just in case. One thing though, you must have trust but I can see how this could be a little awkword. That is all the advice I can come up with. Protect your heart but don't be too upset. If she decides to return o him, that's her loss not yours. You was good enough to accept this...most people wouldn't. I'm sorry if this doesn't help. I'm here if you need to chat!