spam filter

This is about that first email that is sent out by Drupal sites to newly registered Drupal users, welcoming them and telling them what their initial user name and password are.

We've found that:
1) these emails often end up in people's junk/SPAM folder (depending on the email client and SPAM filters used)
2) people don't check their junk/SPAM folder enough, so many never return to our site

Apart from more clearly stating on the registration form that newly registered users should check their junk folders, we've been wondering what can be done to reduce chances of this happening?

Jag har stora problem med att skapa nya poster och kommentarer som innehåller kod. Jag kommer aldrig förbi spam filtret. Är det någon annan som upplevt detta?

Jag har även försökt maila Orjan min lösning utan att lyckas (spam filtret hugger där också!).

I'm logged in as hallman on groups.drupal.org and trying to comment on a post --
http://groups.drupal.org/comment/reply/26213 -- and get the message:
"Your submission has triggered the spam filter and will not be accepted."
This is what I'm trying to post...

Attempting my first major upgrade