Mandrill Blog We're Making Domain Verification Mandatory

We're pushing a change today, August 4, 2015 at 12:00pm UTC (see this in your time zone), that makes domain verification mandatory when you add a new sending domain and set up SPF and DKIM. This change won't be applied retroactively, so if you added a domain to your Mandrill account before today and set up SPF and DKIM, we'll still sign your mail as usual. However, we still urge you to verify any sending domains for your account.