Mass emails are great for and should be used for 1 purpose and 1 purpose only....to alert/inform a large group of people. That, in my opinion, is it. I feel like when people receive mass mailings they sometimes forget what the intention of the email really was. It's not an opportunity to catch up with someone else in the chain in front of everyone else. It's not an opportunity to get your 15 seconds of fame by trying to make a witty comment or joke. If thats the type of attention you seek...start a damn blog. Then you can say whatever you want, have your reader's full attention and know that the individuals reading are at least half way interested in whatever nonsense you have to say.
I can't understand why people hit "reply all" when they have a specific comment to the sender or the last person that made a comment when their comment and/or question has nothing to do with the subject of the email.
If what you have to say pertains to the whole group... AWESOME. If not, there is a good chance that everyone else 1. doesn't need to know...2. doesn't want to know...3. couldn't care less.
I tried to bite my tongue...I really did...