I get a surprising number of emails from developers testing some sort of emailing system and wondering if its "ok" to send those emails to Mailinator.
Of course - the answer is yes!
In fact, thanks to an email from one of those developers named Dave, I've actived port 587 on Mailinator to be an active receiving port (in addition to port 25).
Mailinator has always accepted email addressed to any domain - (i.e. have a domain name? point your MX record to the mailinator server and it will arrive just fine) so it really is a pretty solid testbed. Remember, you can see the raw email (headers and all) by clicking the "text" link on any mailinator show-email page.
The only caveat here is that Mailinator's defenses don't come down ever - even for testing. If you want to send a few thousand emails to Mailinator, it very well might start throwing emails away. As is sort of our goal - we don't mind spam (actually - given the nature of Mailinator - who are we to even define what spam is?). But we ARE interested in the Mailinator service staying up and running. Any legal (and nice - please read terms of service) use is fine by us - but if Mailinator thinks you're being overzealous, we'll probably side with it :)