email login user id password

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 username 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?

Hi,

I created few users with WiscMail email account and Drupal site is not sending any email to users. I tested with Gmail email account and there was no problem. Gmail account receives user Id and password information. Is there any setting I need to tweak on Drupal site to allow WiscMail users receive this email??

Thanks.