Yes, it's considered manners, and rude and shouting, but some people just want to argue for the sake of argument.

By the emails that I am receiving it is considered rude and shouting by only small percentage of users. The other high percent of users don't care and told me not to pay attention to those few who want to monitor how I use my computer.

Here is excepts from a few

I agree that all caps is considered
yelling, but if I know a person types that way because
they are not proficient at typing...I understand.
Tell them it's a free country
and you can type however the hell you want to, and
they don't like it, they can ignore your posts. I'll
bet none of them can resist reading your messages,
though,

Here is my favorite

Sorry for the delay, been busy at work and just tooooooo busy reading the message board. Personally I don't give a dam how you type, besides, if caps are shouting, I have hearing aids and it helps me read it louder.

And here is my etiquette

"Send an e-mail in all UPPER-CASE. Use of upper-case words is the equivalent of singing in a monotone voice. ONLY use upper-case words when trying to make a point (such as I just did). Even at that, you should be careful with who you are exchanging messages"

And I can't sing or type very well!