You've probably seen a lot of email service providers advertise "98% deliverability" or "high deliverability" or "the best deliverability ever," and you might be wondering, what exactly is deliverability? Here's our definition:
de • liv • er • a • bil • i • ty (dih-liv-uh-ruh-bil-i-tee),
A measure of success at which an email marketer gets an email campaign into subscribers' inboxes.
Deliverability involves anything that touches email delivery: ISPs, MTAs, throttling, bounces, junk and bulking issues...you name it. Not to mention, senders affect deliverability—so if you create good content and maintain a clean list, your campaigns will be more likely to reach your subscribers. There's more to it than CAN-SPAM compliance. Think of it like driving a car: CAN-SPAM compliance is a license that allows you to drive, but it can't keep you from crashing. MailChimp provides your engine—but you have to be a responsible driver.
Because the data varies so widely, deliverability is a complicated concept to wrap into a tidy little number. But at the end of the day, we're talking about getting emails to inboxes, and you want to know MailChimp's success rate. We've got charts showing specific deliverability history for some of our awesome clients.
But deliverability is more than numbers and charts, so here are the facts:
Our powerful abuse-detection technology keeps our system clean by predicting bad behavior in a campaign before it even gets out the door. We compared more than 61 trillion data points, using a genetic pairing algorithm running on a cluster of EC2 servers, to create Omnivore. Our email genome project is constantly at work in the background, analyzing emails, absorbing new data and preventing abuse on a massive scale. This means better deliverability for all MailChimp users.
Large corporations and financial institutions are constant victims of forgeries and phishing scams. In order to protect their reputation and prove their emails are "authentic," they use authentication technology in their email campaigns. Some ISPs are beginning to filter incoming email based on authentication. MailChimp customers can add authentication to their campaigns free of charge, by simply checking a box (unlike some other services, there's no server setup required). We support all the major authentication standards: DKIM, SenderID, Domain Keys, and SPF. MailChimp is also a member of the Authentication and Online Trust Alliance (AOTA).
To protect our overall deliverability, MailChimp uses hundreds of IP addresses that are grouped into different reputation levels. Which IP group your emails get sent from depends on your list's reputation score. We regularly monitor our IP acceptance rates using ReturnPath, a leading third-party deliverability vendor. Depending on which group of IPs email is sent from, inbox acceptance rates range from 96% to 99%. Check out our IP address ranges right here.
We can send to extra-large lists, and we provide full authentication for those large accounts to use their own domains. We know it takes some time to break in new IPs and make ISPs trust them, so we automatically warm up our dedicated IPs.
We're registered with all the major ISPs to receive alerts whenever your recipients report your campaigns as junk or spam. These alerts that we receive are part of what's called feedback loops. When that happens, we instantly unsubscribe those members from your list in order to keep you (and MailChimp) from being blocked in the future. We're on feedback loops with AOL, Hotmail, Comcast, Yahoo, USA.net, Cox, Earthlink and more.
Even though most ISPs are transitioning to feedback loops, some still employ whitelists. MailChimp is registered with them and actively works to maintain our whitelisted status.
We employ algorithms that scan our system for signs of abuse. But we also employ a human review team who can, in the blink of an eye, detect subtle cues about a user (there are roughly 30 different characteristics we've learned to look for) that can jeopardize our deliverability. The review team is empowered to suspend accounts and contact users about any risk factors they need to address.
MailChimp is part of the deliverability dialogue. We stay on top of industry and technology standards by being active members in email and ISP organizations such as the ESPC (Email Sender and Provider Coalition), AOTA (Authentication and Online Trust Alliance), MAAWG (Messaging Anti-Abuse Working Group), and EEC (Email Experience Council).
With one click, MailChimp users can scan their email campaigns for content and coding red flags that can cause deliverability problems. By preventing bad campaigns from leaving our system, Inbox Inspector improves our system's deliverability.
Our Inbox Inspector will tell you if your campaign will get blocked by spam filters, but it's trickier to diagnose the reasons why your campaign will be blocked. Is it your links? Images? Content? Our Delivery Doctor tool will automatically run tests and analyze your campaign until it finds the root of your block.
Get started with our Expert Exchange Program, and we’ll reimburse you for up to 50 percent of the cost.