If he wanted to ease your pain he would END the divorce proceedings until you were BOTH on side with the idea.
i would put that to him immeidiately.
I don't like the fact that you are pursuing divorce without my consent. I think that ending a marriage should be a mutually consentual decision don't YOU? I would like you to end that right now until we have had time to sort things out properly.
Something like that.
If he is REALLY sorry he will do that.
And talking via email is WORSE than in person in my opinion. In person in the open public at work, particulary if others are present the convo wont' stray into "I miss you" or sexual innuendo... email is VERY easy for them to take advantage of unlike in person in public when its a lot harder.
If he was really sorry he would explain to management that he can't work with her anymore and wants to be put in separate projects from now on.
There is NO NEED for him to be in any contact with her at work if he's really willing to work on repairing the damage here.
You have to realize how EASY it is for this to start up again. Especially as the divorce looms closer...
Acting sorry is one thing, but putting up a wall to her at work is another. I just think he could do a lot more to set your mind at ease there... You want to just trust him, but I have seen too many of these things end and start up again later... They don't end quickly, particularly when contact is continued at any level at all.