10 Things Every Sender Should Know About Email Delivery [Twilio SIGNAL recap]

March 31, 2020
Written by
Lauren Kaye
Opinions expressed by Twilio contributors are their own

10 Things Every Sender Should Know About Email Delivery [Twilio SIGNAL recap]

How can you improve an email program that’s currently seeing moderate success? It’s truly a million dollar question. 

When you consider that email generates $38 for every $1 you put into it—and that most companies send thousands of emails at a time—it’s easy to see how even small improvements can have a tremendous impact.

To help you get the most out of your email program, our team of email delivery experts sat down at Twilio SIGNAL 2019 to share some of their best insights. Check out the video to see how they answered questions about improving email delivery or read on for 10 highlights from their panel. 


1. You’re not getting 100% of your emails to recipients

Surprise—even if it looks like you’re getting full delivery rates and you don’t have any spam reports, chances are good that some of your messages are not making it to recipients. 

Some emails get filtered into the junk folder or spam filter behind the scenes. And in many cases, your recipients won’t even realize they’re not getting your messages. 

This can happen even if you’re following best practices. Because, according to our experts, mailbox providers like Gmail and AOL, Yahoo! and Microsoft, make case-by-case decisions about which emails to show to each of your recipients.

2. Each mailbox provider is different

Gmail looks at email with a different set of criteria than Hotmail does. The same goes for Verizon media (Yahoo! And AOL) and Microsoft. If you’re not monitoring your delivery rate for each provider and making changes to satisfy each, you probably aren’t getting optimal delivery results. 

When our delivery experts work with clients, they monitor how the company’s email is performing across all of the mailbox providers. If we notice a dip with one, but not the others, we’ll try to isolate variables and fix what might be impacting their delivery rates and performance. 

Download our 2019 Deliverability Guide for a deeper dive into the differences between mailbox providers and how they impact your delivery rates.

3. Your mailstreams have different reputations

You should keep your transactional messages and marketing messages separate because they have different reputations. 

Transactional emails are typically sent because a recipient requests a certain action–like requesting a password reset or making a purchase. The recipient wants to get those messages, so they usually have high open and engagement rates. Mailbox providers see these as positive signals that factor in your reputation and make sure those messages make it to recipient’s inboxes.

Marketing messages fall into a gray area. Despite your best efforts to make promotional messages valuable to recipients, they aren’t universally wanted. As a result, they may have lower engagement rates that mailbox providers factor into your reputation. 

That’s why separating email streams is one of the first things our experts recommend when it comes to improving your email performance. Specifically, you should have each type of mail on its own IP address to keep reputations separate.

By decoupling your email streams, you can increase the chances that they won’t miss a critical message like an account alert or bill if your reputation for promotional messages isn’t as strong. Also, you get a chance to monitor how your audience interacts with each stream to better understand their preferences and identify ways to improve your program as a whole.

For more details on marketing vs. transactional mail, check out this post from our Expert Services team.

4. You need to prep for holiday sending months in advance

If end-of-year holiday sales are big for your business, our experts suggest you start planning in spring or summer. Fall is too late. 

This precaution is not only to preserve your sender reputation as you schedule large-scale holiday campaigns to drive sales. It’s also that you’re likely going to have higher-than-average account activity that’s triggering welcome emails, password resets, purchase confirmations, etc. 

As you start sending more promotional emails to more people than usual, mailbox providers might read that as a negative signal and it can impact your inboxing rate for both transactional and marketing messages.

As you start sending more promotional emails to more people, mailbox providers might read that as a negative signal.

Combat negative signals by planning a volume ramp. Send more messages to more recipients on your list over time—versus all at once.

If you can do this while continuing to maintain engagement rates, you’ll be in a better position to successfully get messages delivered when you really ramp up your volume for the holidays.

5. You’re being compared to world-class senders

When mailbox providers decide where to place emails s, they’re comparing you to all other senders. That includes global brands with sophisticated email programs that send hyper-personalized email messages to every recipient. 

It’s intimidating to know that you’re going up against the best of the best for inbox visibility. In your case, it may not be possible to create a world-class email strategy overnight with one-to-one targeting and dynamic content—and that’s ok. 

What matters most is that your email is wanted by recipients. If you’re getting that fundamental principle right, you can still earn your spot in the inbox alongside bigger brands.

Here is a report we compiled to help you understand what it is that email recipients want: 2019 Email Benchmark and Engagement Study.

6. Sunset policies are non-negotiable

Sunset policies are a way to keep people who aren’t engaging with your emails off your list, so you don’t send unwanted mail to recipients.

Most companies have a sunset policy for last interactions. For example, you might remove recipients from your list if they haven’t opened an email in the past 6 weeks. 

That’s a great start, but we also suggest first-interaction policies to keep your list free from incorrect email addresses, abandoned accounts, or honeypots. With a first-interaction policy, you remove any addresses that they don’t engage with the first few emails you send after they opt in (think: confirmation emails and welcome messages) to keep them off your list from the start.

To learn how to set up a sunset policy for your email program, read through our post on how to create and execute an email sunsetting policy.

7. Authentication is email 101

If you can only do one thing to improve your deliverability, you should authenticate your emails. Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM), and Domain Message Authentication Reporting & Conformance (DMARC) are protocols that tell mailbox providers that you are who you say you are.

  • SPF authenticates a sender’s identity by performing a check similar to verifying a return address
  • DKIM authenticates a sender’s identity AND checks to confirm that the contents of the message haven’t been altered 
  • DMARC confirms the messages meet SPF and DKIM requirements before they are delivered

If you only do the bare minimum email program, this is what you should do to improve your sender reputation with mailbox providers. See how email authentication works for a deeper look into why setting up these protocols is critical to your delivery rates.

8. Your reputation follows you

If your delivery rates are struggling because of a poor email reputation, getting a new IP address seems like an easy fix. You just use an IP that’s completely unassociated with your current engagement signals. 

In reality, it’s not going to get you very far. Although a new IP won’t have a poor reputation associated with it, it’s a band aid solution.

Our email experts point out that without a wholesale change to your email program, you bring your bad practices with you and before long, your new IP address will have the same reputational signals as your old one. 

There are, however, good reasons to get a new IP address. You can find them here.

9. Your opt-in process must be transparent

How are you introducing your emails to new recipients? A transparent opt-in process is the best way to set expectations from the start so recipients know what they’re signing up for. It’s also an opportunity to let them choose what kinds of messages they’d like to receive and how often. 

If you don’t have a clear opt-in process, you could be adding people to your email list who don’t want to be there. Trust us, you don’t want those people on your list. 

The more messages you send to unengaged recipients, and the more they let those messages linger unread in their inboxes or relegate them to the spam, the more it will look like you’re sending unwanted email.

10. Your emails are being tested

Mailbox providers might send your emails to the spam filter as a test. If the recipient goes looking for them and drags them back to their inbox, you pass and your messages will go there in the future. 

However, if the recipient leaves your messages in their spam filter, mailbox providers take that as a sign that they’re not that wanted. Your messages might continue going there as a result—and you won’t even get spam notifications to warn you that this is going on. 

It’s not easy to achieve a strong delivery rate. That much is clear. To actually get your messages in front of recipients requires a lot of work and dedication that goes beyond creating interesting email content and crafting clever subject lines.

Our Expert Services team works to uncover the trends and changes that are impacting our customers’ deliverability behind the scenes. They sit on major compliance and delivery organizations such as M3AAWG, ESPC, DMA, and EEC so we can learn about best practices and, in turn, educate senders about the right (and wrong) ways to engage recipients. Learn more about our email experts and the services we offer. 

If you enjoyed these highlights from Twilio SIGNAL 2019, you can continue watching our recorded sessions on YouTube. To attend SIGNAL 2020 (now postponed until 9/30-10/1) and see email strategy sessions in person, you can register here.

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