My experience has been that much of the time many emails go to the spam folder because the user has not added your website email to their safe list.  This is something very common now days and you really should not panic over it.  Many email clients are getting tougher and tougher and sending more email to the junk folder to try to head off actual spam.  Sometimes good email gets caught in the mix. 

The best thing you can do is to have the users add your site mail to their safe list.  You can also edit the language if you want in admin to have the message on the screen remind them when they register to check their junk mail.  

Eventually what may happen is that when you get enough people that have added you to their safe list the email clients may back off a bit and learn that your email is not junk. 

Hope that helps you ;) 

Mine were all dumped into spam because they started with 'Dear' which is something spam programs filter for...

That said, go into admin, look at the 'Settings' option, then click on 'Language' and search for a text string you know is in the mail you want to edit. 

It will show up and you can edit it there.

Hope that helps you out.

cheers,

Bridgette