Why do I need to send my email to multiple addresses?
Since our spam filter testing now tests for reputation scoring, we now require you to send to multiple 'seed' email addresses for scoring. It's important that you send from the same place you'll send your actual campaign from. For example, if you use an Email Service Provider to send your monthly newsletter, make sure you use their 'send a draft' form to send to our seed addresses. That way, we'll be testing yours and your ESP's reputations accurately.
While you're in the earlier stages of designing and proofing your email, you can continue to send to a single address or upload your email's HTML. Just don't check the spam option when creating a test, and Litmus won't offer you the additional seed addresses.