Why am I getting spam from someone at vhdev.com?

The simple answer: You're not. Someone is using random @vhdev.com to send their outgoing spam mail.

The more complex answer: Someone is "joe-jobbing" us. The term "joe-job" is used to describe a spam gang using someone else's email address or domain name for an outgoing batch of spam. You see, the "From:" address on an email is trivial to spoof or fake. Anyone can use anyone's address to fake the email - that is one of the inherent weaknesses of our current SMTP standards. There's simply nothing we can do about it.

Rest assured, the spam email did not come from us - it is fake. Looking at the full headers of the email you may have received will show you the truth - it was sent by someone else, with a faked "From:" address.