Edit: To those who are downvoting - the comment to which I'm replying says:
> Or a tool that just generates random
> mail addresses ending with a popular
> e-mail provider domain.
Firstly, the address does not end with the domain of a popular e-mail provider, hence the email address to which I'm receiving these unwanted emails is not of that form. Thus my reply is true, and informative.It's also neither a random user at the domain, nor a dictionary element, nor a simple variant on a dictionary element, nor short, nor public (until now), nor falls into any of the formats I see and deduce from the dictionary attacks on the servers I run. And it is long, and has internal structure. Thus is is, again, not of the form being described in my comment.
So thank you for the down-votes, but I feel that my comment is true, relevant, and justified.