My concern is that if (when) your service gets popular, sites that require registration won't allow email addresses with the mailop.com domain (if they want real email addresses).
Yeah. 10MinuteMail.com rotates out domains every month or two.
The problem is that people who actually care about blocking temporary e-mail tend to stay on top of the big sites domain lists. There are even 3rd party lists you can integrate your site/forum with that block all disposable addresses.
My concern is that if (when) your service gets popular, sites that require registration won't allow email addresses with the mailop.com domain (if they want real email addresses).
Other than that... great for you!
-Artel