Email Deliverability: 6 Common Email Myths Debunked

June 06, 2023
Written by
Samantha Stinn-Shelley
Opinions expressed by Twilio contributors are their own
Reviewed by
Ravleen Kaur
Opinions expressed by Twilio contributors are their own
Chelsea Coster
Opinions expressed by Twilio contributors are their own

Email Deliverability: 6 Common Email Myths Debunked

There are many email deliverability myths out there that customers have come to believe as they try to make sense of their deliverability on their own. Understanding email deliverability without an expert can be difficult – and that’s why we want to dispel these common misconceptions. 

Email deliverability misconceptions

Let’s take a look at some common email deliverability myths and why they’re false.

1. Deliverability vs. delivery

“Delivery” indicates mail was accepted by the inbox provider. The delivery rate describes how many messages were accepted against the total messages requested (or sent). There are various reasons a message can be undeliverable, such as an invalid email address, which would impact a customer's delivery. Deliverability is what happens after a message is accepted for delivery by the inbox provider. For example, a message might land in the spam folder, the main inbox, the promotions tab, or simply get dropped on the floor, entirely disappearing. Inbox providers have sophisticated filtering systems based upon a customer’s sending practices and reputation, and the customer may have good or bad email deliverability based upon the reputation that they have established.

2. 100% deliverability is possible

In an ideal world, an email marketer would want every single person on their list to see every email they send. This is impossible for even the best of email senders. Most lists will contain addresses that are undeliverable. Bounces, blocks, and deferrals are an expected part of sending email. Once an email has been accepted for delivery, these emails are put through the complex filtering algorithms. These algorithms take into account several different factors based heavily upon previous recipient engagement. They will do everything they can to keep wanted messages in the inbox and unwanted mail in the spam folder. 

3. Adjacent reputation and deliverability

Senders in shared IP pools are often concerned that the other senders with poor reputations in the pool are impacting their deliverability. While it is true that senders are grouped on shared IPs with other senders that have similar sending behaviors, and that some reputation issues like blocklists can cause delivery issues for an entire pool, we have found that senders can have good email deliverability regardless of their pool. Senders have minimal impact on each other's sending in these pools.

In fact, over the years we are seeing proof that inbox providers are becoming more sophisticated at email quality detection and filtering. They are getting better and identifying our shared pools and treating senders as individuals. Inbox providers analyze all activity they see from an individual sender and work to keep wanted mail in the inbox and unwanted mail out. Today, even in our “worst” performing pool, we are seeing nearly a 90% delivery rate. This indicates that the majority of the mail on this pool is being delivered. With the inevitable bad mail on the pool being rejected for various reasons, we are seeing little to no mail being rejected on pools due to other senders' behaviors. If senders want to improve their deliverability, they’ll need to focus on fine tuning their email practices

4. All blocklists have equal impact

Blocklist monitoring tools like MxToolbox will alert senders to any and all blocklists regardless of impact. This often causes a sender to panic when they have any sort of blocklist on their IP because they have been taught staying off all blocklists is critical to good email deliverability. We commend senders for laying down the foundation for understanding their email program; however, not all senders should be concerned with blocklists equally.

Anyone can create a blocklist, but that doesn’t mean it has any impact on a sender. A blocklist truly matters when an inbox provider is using the data provided from this blocklist and blocks resulting from this blocklist are significantly impacting this sender from getting to the inbox. If a blocklist is making an impact, we will see this reflected in their block events.

Reputable blocklists, like Spamhaus exist to encourage senders to change their sending habits to stop the poor behavior they are observing. We recently explained the latest increase in Spamhaus listings. Many inbox providers will then choose to utilize the blocklist data feed to help filter the mail to the inbox. This is not true for all inbox providers, though. Gmail, the world's largest email provider, does not use blocklist data and only relies on their own sophisticated filtering algorithms to place mail in the inbox or send it to spam. 

How do you know if a blocklist is worth being concerned about?

The sender should understand the impact of the blocklist. Are they seeing a significant amount of blocks accruing from a single domain due to this listing? Based on that, the sender can assess if a blocklist is concerning. 

How do you know if a customer should request a delisting? 

A blocklist will refuse to delist a sender if they are still seeing poor sending activity. The only way to delist will be to implement stricter policies. For some senders it may not be worth eliminating large parts of their list in order to make this blocklist happy. A sender needs to weigh out the pros and cons of what it would take to get delisted. In many cases, the cost of reducing your list size and doing more aggressive sunsetting simply isn’t worth the benefit of getting off of a blocklist. Spamhaus is the only exception. It is always worth taking actions to mitigate a Spamhaus listing. 

5. Low spam complaint rates indicate good deliverability

Spam complaints are just one metric of email program performance. When looking at performance at the campaign level or by inbox provider, trending high complaint rates can be an indicator that recipients are reluctant to receive this content; however, the opposite is not always true. If messages are getting filtered heavily into the spam folder, then people will not see them and they won’t mark them as spam. 

Spam complaints only happen when someone marks a message as spam in their inbox. This data does not include messages filtered to spam. Sending test messages is a good way to indicate message filtering along with better understanding the data around a sender's open rates. A combination of low opens and low spam complaints could be an indicator of messages being filtered to spam. 

Gmail does not provide a traditional feedback loop. SendGrid will not receive spam complaints back from them in the same ways we see them from Microsoft for example. If you do see spam complaints coming from a Gmail address, it is due to the message being forwarded from a non-Gmail address, then being reported as spam from the forwarded Gmail address. To better understand performance at Gmail, sign up for Google Postmaster Tools.

6. Unsubscribes are bad

It’s easy to understand why a sender believes unsubscribes are bad: they want to keep as many people on their list as possible. Unsubscribes are actually not inherently bad. It’s a good sign that recipients are following the functionality of unsubscribing from messages they no longer want to receive. We would rather see high unsubscribe rates than high spam complaints. Inbox providers have also never indicated that they use unsubscribes to filter or place poor reputation on sending.

As with all metrics, senders should look for deviations and trends in their data. If you are concerned about high unsubscribe rates, try looking at what campaigns are causing the highest number of unsubscribes. Additionally, you can better understand how those addresses are collected and at what frequency they were communicated with previously. Recipients will always be sensitive to receiving too frequent communications, especially from brands they haven’t heard from in a long time. A dynamic email marketing lifecycle that changes frequency based on how people engage with a sender’s brand is key to good email deliverability.

Senders concerned with high unsubscribe rates should consider implementing a preference center when unsubscribing to allow people to opt-down for less frequent communications. This can be a useful way of keeping people on their list for longer. 

Understand and uplevel email deliverability with Twilio SendGrid

Email deliverability is complex, but awareness of the common email deliverability myths can help you build a strong foundation for your email program. If you’re looking for more customized advice for your email program, reach out to our Expert Services team. Our deliverability experts offer various levels of assistance to help our customers better understand the performance of their email program and reach their maximum potential with SendGrid.

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