When you’re as essential to your customers’ success as Mailgun (whole apps are built almost entirely on top of it, and a suspended/cancelled Mailgun account could affect thousands of Mailgun’s customers’ customers), you can come right out of the gate with a mildly threatening email (which kindly informs the customer that if their account is cancelled, all of their data will be lost), because you know that your customers will probably update their billing information immediately. I got this one, and I immediately updated my card. I don’t even know what the rest of their sequence looks like, which is kind of my point here.
Subject: Mailgun billing error Hello, We received a billing error for your credit card: Your card was declined. Please update your billing information in the Control Panel (https://mailgun.net/cp) as soon as possible. If you do not update your account with correct billing information within 7 days, we reserve the right to cancel your account permanently and all of your data will be lost. Thank you, Mailgunners