I suppose its possible, but it would involve a hacker breaking into the server, installing some other email server (which would likely conflict with mailinator itself), configuring it, and then start pummeling it for their nefarious purposes. Given that any self-respecting spammer has a billion zombies at their disposal and that this would definitely be discovered very quickly (my colo vendor loves to watch my bandwidth), it doesn't seem like an efficient way to spam.
In any case, I still get accused of spamming at times. And all that accusation takes is for a spammer to forge the return address as a mailinator address. Let me tell you, forging a return address is stunningly easy. Here's 3 million or so guides how to do it if you're wondering.
Below is an actual email header someone sent me.
The interesting parts are really the first two lines. As you see the forged return path is firstname.lastname@example.org. Now if you know mailinator, you know ANYONE can check that box. It belongs to no one and everyone (as outlined in the FAQ - Mailinator guarantees NO PRIVACY. All emails are viewable by ANYONE).
The 2nd line (i.e. Received:) shows the IP (and dns) of the server that actually sent the email. Something at abac.net. That looks like a hosting company somewhere. One thing I can tell you though is that that server has zero to do with mailinator. The spam email never ever touched the mailinator server. So even if I devoted my life to stopping this email, there's nothing I could do.
Received: from 18.104.22.168 (216-55-169-94.dedicated.abac.net
by smtpin4.mail.de.uu.net (8.14.1/8.14.1) with SMTP id n083RPV6001157;
Thu, 8 Jan 2009 03:27:26 GMT
From: "RON" email@example.com
Reply-To: "RON" firstname.lastname@example.org
To: xxxxxxxxxxxxxx --> edited
This is sort of similar to a phishing attack. Someone gets an email from their bank, then goes to the phish site, then loses all their money. In truth their bank had nothing to do whatsoever with any of that but the bank still gets blamed.
The saddest part for me is that even after I respond to people showing them the real culprit, its not uncommon for them to stay mad at me. I suppose its because they then don't know who they're going to yell at now and I'm still available for the job.
Mailinator is about letting you protect your real email address. It might be to prevent spam but at times it might even be to receive spammy email they really want (just not at their primary address).
Regardless what you use it for, it won't email you. It just doesn't do that.
Plenty of people threaten to blacklist Mailinator from ever sending them email again. Yes, please do! As I've said in the past, feel free to put mailinator.com on the tippy-tippy-top of all your spam blacklists. Mailinator doesn't send any email at all - so you can be sure any email that looks like it came from a mailinator address is forged. And I'll sleep just fine if such email gets blacklisted.