I have a different twist on this.
I think you have NO REASON to be alarmed about using this email since it was YOUR email address. You did nothing wrong! You were not spying into the email of your EX. It was yours. (Can't help it if he's too damn dumb to know he should have his own private one from his ex-wife).
You could be distraught and anguished in reading this because WHAT IF this reflects the attitude of everyone there INCLUDING THE ELDERS who have the power to reinstate you or NOT reinstate you. You could use this to go to the Elders and ask if this is what THEY really think of you too??? In fact, I'd wait until the CO is here and take it to him. Or, better yet -- send a letter to the Service Department.
Ask them if this brother is REALLY spirit appointed if he has this attitude.
Ask them if this is the attitude of everyone in this Cong, how can you really get a hearing ear from the Elders?
Ask them if this is why your reinstatement has been SO LONG in being approved?
Ask them if you will be forced to change Congs in order to be reinstated?
The Service Dept will send a copy of your letter and the email to the CO and to the Cong.
OR ---- start with just going to the Elders and tell them you thought maybe you should send it to the CO or the Service Department, if everyone felt this way? Because how could you ever be welcomed back into Jah"s Org if they had this attitude.
I think it could actually be used to generate some sympathy for you. And it sure as hell should get the little dickwad MS booted.