Twilio SendGrid's Deliverability Insights is a streamlined in-app dashboard that provides an actionable view of your email delivery performance over time.
Email is a data-rich channel, offering critical insights that can help you better serve your audience. However, parsing and interpreting that data is often difficult. That's why we created Deliverability Insights.
This documentation will help you understand Deliverability Insights and how to take action based on the data it provides.
Deliverability refers not only to getting your messages accepted by mailbox providers, but also to reaching your recipients' inboxes — not their spam or junk folders.
To view your Deliverability Insights dashboard
Deliverability Insights data is not provided in real-time. You should expect your dashboards to be up to 48 hours behind real-time data. For real-time event data, you can use the Twilio SendGrid Event Webhook.
Deliverability Insights provides four view tabs to help you understand if you're reaching recipients' inboxes, and, if not, why.
The following documentation is organized into sections that match the four Deliverability Insights tabs to help you work with your metrics effectively in each.
Every sender has different key metrics to watch, but the following primary deliverability metrics are important for every sender to monitor at a high level, which is why they are presented on the Deliverability Insights Overview tab.
While these numbers don't tell you the whole story, it's rare to have a significant deliverability issue that doesn't appear in these metrics.
The Processed metric represents the number of messages you attempted to send through your Twilio SendGrid account. Twilio SendGrid considers a message processed once it successfully reaches the SendGrid system and SendGrid attempts to deliver the message. However, not all processed messages are successfully delivered.
The Delivered metric represents the percentage of messages that were successfully accepted by your recipients' mailbox providers. Getting messages delivered is the first step towards good deliverability. When a mailbox provider accepts a message, it is then up to the mailbox provider to determine what to do with that message. The mailbox provider has a few options.
Place the message in the recipient's spam folder.
Place the message in the recipient's primary inbox
Place the message in the recipient's non-primary inbox tabs
Accept the message and then delete it.
The Bounced & Blocked metric represents the percentage of messages that were not successfully delivered.
A Block indicates that the message was not delivered for a reason other than being bounced.
Knowing which direction your overall bounced and blocked rates are trending is a great start. Understanding bounce and blocked metrics is detailed in the Bounces & Blocks section of this document.
The Unique Opens metric represents the percentage of delivered messages that were opened. Unique open rates are a key performance indicator (KPI) for many email programs. Watching for trends in your unique open rates can help you spot deliverability issues. For example, if you made no changes to your sending behavior but your unique open rate is falling, this could indicate that one or more mailbox providers is sending your email to the spam folder.
Watching trends in your metrics over time is invaluable. If there is a clear date when a metric changed, look into what might have changed in your sending behavior on or around that date.
The Deliverability Insights Overview chart is a great starting point for any investigation into your overall deliverability performance. When you spot an increased block rate or a falling open rate, you can then use the other Insights sections to dig deeper.
If you see a decrease in your deliverability rate
This further investigation is useful because it helps you understand if the problem is isolated to a few mailbox providers or if it is widespread, which informs how you address it going forward.
Bounces and blocks are paired in the Overview section of Insights because they both represent messages that were not delivered. However, bounce events and block events are different failure classifications, caused by different issues, requiring different solutions.
If you see an increase in bounce and block rates
Bounces happen when you attempt to send to email addresses that are not valid.
If your bounce rate increases
Determine whether anything has changed with the way you collect email addresses.
Inspect your signup forms.
If your block rate increases
If your open rate decreases
If your open rates are dropping consistently across most of your top mailbox providers, the decrease is likely the result of organic loss of interest in your content or email fatigue. In this case, reduce your sending frequency, rethink the types of messages you are sending, or both. Are these messages still relevant? Is your offer compelling? Are people losing interest in your brand?
If your open rates are dropping at one or two mailbox providers only, those mailbox providers are likely sending some or all of your email to the spam folder. In this case, adjust your sunsetting policies, audience targeting, and sending frequency for recipients at the affected mailbox provider(s).
Mailbox providers are companies such as Gmail, Yahoo, and Microsoft that provide email mailboxes to consumers and businesses. Though mailbox providers rely on the same basic principles to determine if mail is wanted, they all use proprietary algorithms to determine if your email should reach their users. It's common for two different providers to reach two different conclusions.
You'll often hear businesses and people refer to the Big 4 or MAGY — Microsoft, AOL, Gmail, and Yahoo. For most senders, especially those sending primarily to North American audiences, these companies will be the four providers they send to most often. However, due to geography, demographics, business model, or vertical, many senders will have a very different Big 4.
The Mailbox Providers section of Insights will surface your top mailbox providers based on your actual sending behavior, so no matter who you send to, Twilio SendGrid will always display the mailbox providers that have the greatest impact on your deliverability success.
It's incredibly important to monitor all of your primary deliverability metrics by mailbox provider because deliverability issues with one mailbox provider do not necessarily indicate problems with all the others. Monitoring at the provider level also helps you hone your solutions when problems do arise. For example, if your Gmail open rates suddenly drop, you may want to adjust your sending behavior to address your Gmail audience specifically rather than making sweeping changes across your entire email program.
In the Mailbox Providers section of Insights we display your delivered rates for each of your top mailbox providers. Having a high percentage of your email delivered to your top providers is a good first step towards healthy deliverability. However, just because a mailbox provider has accepted delivery of your messages doesn't mean they arrived at your recipients' inboxes.
When looking at the Mailbox Providers chart, search for differences in delivered rates among your top providers. If, for example, Gmail and Yahoo have 99% delivered rates and Microsoft has an 89% delivered rate, it's safe to assume that you're doing something to cause Microsoft's filters to mistrust your messages.
Your open percentages should be fairly consistent across your top mailbox providers. If you see a mailbox provider with open rates significantly lower than your other providers, the under performing mailbox provider is likely sending some of your email to the spam folder.
Look for large deviations in open rate across your top mailbox providers. If you notice large deviations across providers, do some or all of the following:
Bounce and block events indicate that an email was rejected by the mailbox provider. While bounces and blocks both specify that your message(s) failed to deliver, it is important to understand the difference between bounces and blocks.
A message bounces when you attempt to send it to a mailbox that doesn't exist. This could be an email address that never existed or an email address that was once valid but has been retired or deactivated. A message can bounce because the local part (the part before the @) is invalid or because the domain (the part after the @) is invalid. When a message bounces, it is a good idea to suppress that address from future mailing. Twilio SendGrid's suppression management system takes care of this automatically, but you may wish to also remove the address(es) from your own internal lists.
Mailbox providers consider excessive bounces or spikes in bounces to be an indicator that you are sending unwanted email. Twilio SendGrid likes to look at bounces at each mailbox provider because each provider has slightly different rules for determining if an address is valid. For example, some mailbox providers ignore periods in the local part of an email address.
Excessive bounces are generally related to your address collection practices. When collecting new email addresses, follow these best practices and tips.
Check to see if your overall bounce rate is consistently over 5%.
Like bounces, block events indicate that a message was not delivered. Unlike bounces, a block does not indicate the recipient's address was invalid. Rather, it means that your message failed because of content and reputation issues or technical failures.
If a mailbox provider has reason to believe that you are sending unwanted email, they can decide to block your messages. Common reasons a message may be blocked for content include:
Detection of suspicious HTML characteristics.
If there is a technical failure, a message may become undeliverable. Common technical failures that can result in a block include:
Like most other email metrics, it's important to monitor your blocked emails in aggregate as well as by mailbox provider. Remember, just because one mailbox provider is blocking your email does not mean that other mailbox providers are doing the same.
Look at your distribution of blocks by mailbox provider.
The systems that return spam report data to senders are called Feedback Loops (FBLs). A spam report event is logged any time a user hits the "Report Spam" or "This is junk" button for one of your messages. Mailbox Providers, most notably Gmail, do not send back Spam Report data. Twilio SendGrid is automatically configured to collect spam report data from all mailbox providers that offer it. Your only job as a sender is to monitor your complaint rates (in aggregate, and at your top mailbox providers) and keep them as low as possible. Most deliverability experts consider a spam report rate above 0.1% to be excessive. To reiterate, this means a spam report rate of 0.1% or higher at any single mailbox provider is a potential deliverability risk.
As mentioned earlier in this section, some mailbox providers do not send spam report data back to the sender. This makes monitoring complaint rates by provider essential. Sudden spikes in spam reports can dramatically lower your reputation and deliverability.
There are a number of things that cause a recipient to hit the "Report Spam" or "This is Junk" button, including:
example.com
newsletter, they don't expect to receive email that looks like it came from
otherexample.com
. Make sure recipients know this message is from the organization they signed up with.
Unsubscribe rates can provide great insights into what your recipients think about the email you are sending them. When you see a spike in unsubscribe rates, investigate what types of mail you sent around the time of the spike. Try to determine why this message or campaign might have missed the mark and why it caused more users than normal to unsubscribe from your mailing list.
Unsubscribes are not directly impactful to your deliverability or your reputation. However, if unsubscribes are high, it is a great indication that your email isn't resonating with your audience. Therefore, addressing increasing unsubscribe rates can help preempt actual deliverability and reputation issues.
Attempting to prevent people from unsubscribing is a bad idea. No one likes to see high unsubscribe rates, but unsubscribes are better than spam reports. Every organization that sends commercial email should give users a quick, reliable, and trustworthy way to unsubscribe from their messages.