To be honest I don't know what they are doing. They were using SpamAssasin until a few weeks ago, then they stopped. Now they are using something called X-DefendMail.

In their CPanel setup, they don't have any settings, but the whitelist, blacklist and keywords for their confirmation system.

I was getting 100 spams per day, but now none, and their CPanel logs only shows about 5 confirmation emails sent over a week's time. So.....I guess X-DefendMail must only send confirmation emails in a small number of "indeterminant cases".

To be honest I have no idea what they are doing, but my original point still stands, that obfuscating your email address will only have minimal impact on the amount of spam your get, for various reasons.