Mandrill should handle several hundred emails per hour by default. Try sending yourself a test email through the nodebb acp. That may push old messages through. The more "bounce back" emails sent. The lower the overall sending quota. But that shouldn't drop it down to 1.
@a_5mith Yep I tried sending test emails. Whenever I registered a new account in mandrill I can only send one email and the rest are queues. Might be an issue?
@jun We've never had to do any actual adjustments to our Mandrill integation. Make sure you are using the correct key (not the mandrill test key), add SPF records, etc?