I have a suggestion for the main site.
When I send a message to the support (what I did today) I would like to get a copy of it per mail.
Mostly I forget to make my own copy and later i don’t know on which day I’ve written the message and what I exactly wrote.
What do you think about this?
Sounds like a good idea to me!
Yes, I would like that too. 
I can see all messages in my sent box.
I’m talking about the main site, not about the forum.
That is a very good idea! 
Sounds like a very useful suggestion!
I definitively feel with @Bille as I sent a message to support just yesterday and regret that I didn’t get a copy via email.
That’s a very good idea!
I support this idea! When I last sent a message to the support team I was missing a “Send-me-a-copy-of-my-message”-option as well.