I'm not sure if this is in the right place, there didn't seem to be a category more suited to it.
Basically, i'm sending emails in PHP using SMTP. They are received by my personal gmail account just fine, but i'd like to do some further testing and put my emails through a validator to check that they're not going to be caught by spam filters.
Does anyone know of a website that does this? Something similar to the W3C's HTML validator would be perfect.