My hosting provider has informed me that spam was being sent from one of my sites because the "Tell a Friend" feature was being used as an open relay - _even though I was not using this feature on my pages_.
 
This could lead to account suspension.
 
If you are not using this feature please change the "Administration > Tell a Friend" option to "Random Image Validation" set to "For all users".
 
If you are using "Tell a Friend" please dont set validation to "Not Used".
 
Ive raised a support ticket to ask for the default in the downloads to be set to the "For all users" option in the database on an Install.
 
If you have version 3.3.2 then please also see
http://www.viart.com/the_patch_for_an_image_validation_on_a_tell-a-friend_page.html
 
Its possible that the Forum settings might need this applied as well.
 
HTH
Ned