If you send email on behalf of clients, you’re familiar with the term “deliverability.” Your clients demand it, and you need to make sure that your agency — and the ESP you’ve chosen — can deliver.
But deliverability is more than just an industry buzzword — it’s a way to measure the success at which an email marketer gets a campaign into subscribers’ inboxes. It involves every facet of email delivery: from the technical stuff like ISPs, MTAs, and throttling, to the aspects that you (and your client) can control, like the cleanliness of a list or an email’s content.
Today, we’ll walk through the steps Mailchimp takes to ensure deliverability for our users. Next week, we’ll turn our attention to things that you can do for your clients to help them reach inboxes.
How Mailchimp ensures fast, reliable delivery
Mailchimp has more than 12 million customers who send 20 billion emails every month to recipients all around the world, so it’s crucial that we have the infrastructure and resources to support that type of volume. For 15 years, as we’ve been developing products that empower businesses, we’ve also been working hard to build out a secure, reliable infrastructure behind the scenes.
Today, we’ve got dozens of servers (which we own ourselves) and multiple MTAs in world-class data centers around the United States. Plus, we’re constantly scaling to prepare for the future. But deliverability isn’t just about hardware like servers, switches, load balancers, and ethernet cable. Here are some of the other ways Mailchimp works to ensure deliverability for your clients:
We’re a member of a number of different industry-wide organizations (ESPC, AOTA, MAAWG, and EEC) dedicated to deliverability and maintaining the email ecosystem. This allows us to stay up to date on the latest industry and technological standards, so we can provide the best possible service to our users.
You’re probably familiar with the ways Mailchimp handles spam complaints, but you might not know that ISP feedback loops and allowlists are a driving force behind that behavior. We’re registered with all of the major ISPs to receive alerts when a campaign is marked as junk, so we can automatically remove the recipients who’ve filed complaint from your clients’ lists. This helps to prevent a recipient from submitting multiple complaints, which can harm deliverability and lead to future emails landing directly into spam folders.
We’ve developed our own abuse-detection technology, Omnivore, that analyzes campaign data and user activity to predict — and prevent — bad behavior in campaigns. Omnivore prevents abuse on a massive scale, which helps us uphold our reputation and improve deliverability for everyone. We also have a human review team that monitors for potential abuse and is empowered to suspend accounts and contact users about risk factors that need to be addressed.
Authentication acts like a license plate for an email — a trackable identifier that proves to a recipient’s ISP that the email is coming from a legitimate sender. Mailchimp automatically adds DKIM and SPF authentication to all campaigns by default, so you won’t need to edit DNS records manually. But if you’d like to set up custom authentication for your clients, you can do that, too. Not sure which type of authentication is the best fit for your clients? This article can help you decide.
Mailchimp delivers email very fast. Like, a million emails in 45 minutes fast. But major ISPs place limits on the number of emails that can be received from an IP address in any given amount of time. Those limits are unpublished, and can be affected by bounce rates, abuse complaints, subscriber engagement, spam trap hits, or any other behavior an ISP deems suspicious. Mailchimp has hundreds of IP addresses. They’re grouped by list reputation scores and have inbox acceptance ratings of 96%- 99%. That’s how we send through multiple IP addresses and account for throttling.