Your question is not very clear, but here's what I interpret.
You want an email address to just receive messages from 10-20 aliases.
It sounds like you should create the one mailbox to which you want to receive messages. Go to your aliases and have the ones you want to go to that box forwarded to that particular address.
All of this can be done in your web panel here.
As for feeling you were treated rudely: You double-posted, which is considered poor manners in most forums (including this one). You pick the most appropriate forum in which to post and limit to that. As a user, wouldn't you be put off by someone posting questions about MySQL in the beginners board?
Besides, you weren't treated rudely. You were asked to "Please" refrain from double-posting. Please seems like a pretty gentle (and polite) request on a board populated by users like yourself and not actual Dreamhost staff.