Okay, that's annoying and I don't think you're overreacting.
Annoying... but...
Anything you post on the internet in any way or email, well, you have to assume that you have let go of control. Seriously. Any email can be forwarded. Doesn't make it right. But it is reality.
If privacy is a big issue, then you should create another email account with no personal info and ignore this type of thing on that board
So while I do get why you are annoyed (especially if the perons in question is a busy body) you have to realize that the minute you post anything anywhere it is public. You don't know who is openly forwarding, who is taking screen shots and sending them etc. and coming from that mentality, yes, you are overreacting. She had a friend or business acquaintance whom she is trying to give business for whatever reason and she took your email as a chance to give that person a heads up.
There is NO private internet. There is totally easy and there is somewhat easy to access, but private? That's an illusion. You have no idea who may or may not have passed along their login info to others, both for non-negative reasons ("Oh, someone on my private board is struggling with the same thing. Hey, just logon as me and you can read about it. Her name is X.") Or for bad/evil ("Oh this person on my private board drives me NUTS. I'm going to send you a screen shot of her latest insanity sp you and I can make fun of her." )
Not cool, still stinks, but not shocking and should be assumed, especially since you already have a read on this person as having poor boundaries IMHO.
Alaina
DS1 12 , DS2 7.5 and DS3 5
Annoying, yes. But you posted on an online bulletin board, it ain't private even if you log in. She sounds like she is Miss Marketer and trying to build connections, cross-market, be uber helpful, etc. Annoying though, I get it. Our neighborhood bulletin board (large urban city neighborhood) has log in and you have to be approved and have connection to neighborhood to be part of it, but I am always amazed at what people post. Also, I am not hannaaddict for my "real" email, I would NEVER use my real email for a bulletin board. I was into Hanna Anderson at the time I found this board and my online mommy bulletin board email was born. Sorry, it does put you on the spot but I think it isn't totally crazy for her to do, only a little.
But, I would guess this person knows her name and her real email address, since it's a small, local board. Our MOMS Club has a Yahoo Group and I have an alias there, but all 40 members have the roster with my name and email. If someone took a post from me to the Yahoo group and used the roster to send my post with my personal information to my friend, I'd be annoyed. I think it's different than me cut and pasting a post from here and sending it to someone.
Kris
OP, I don't know how formal of a moms group you have. However, if it is a MOMS club chapter, there are specific rules regarding using members' information for marketing. We've had to talk to several moms who thought it would be ok to mass market and spam our members. If your group doesn't already have this rule, I would suggest it to the board, to deal with present issues and prevent ones in the future. There are always moms selling this or that, it can get really ridiculous. I would be particularly annoyed with her referring a certain friend and cc'ing the email to that other person, it puts you in a awkward spot and for her to not realize that is really rude.
I am sure that if you have had these bad experiences, that there are other moms in your group who have experienced the same thing. However, until someone actually stands up and says something to stop it, it will just keep continuing and this woman will just continue bulldozing the group with her aggressive tactics. Anyway, I think that you are justified in being irritated by this.
Mom to 3 LEGO Maniacs