How to Troubleshoot Email Deliverability Problems
About 20% of email marketing messages never make it to their destination. It doesn’t matter if it’s a lead magnet, weekly newsletter, or simply a reminder to change your password; the end result is the same.
Your important message is lost somewhere in the process, having failed to reach its intended recipient.
This happens because of any number of issues, ranging from the obvious (your email is outright rejected) to the subtle (the recipient’s mailbox is too full). Fortunately, the root causes of most deliverability problems fall into several broad categories.
As long as you know how to handle each of these problems, improving deliverability and inbox placement rates will be well within your grasp.
Deliverability vs. Email Delivery - What’s the Difference?
Quick clarification, because this trips people up. Delivery just means the receiving server accepted your message without bouncing it. Deliverability asks a harder question: did it reach the inbox, or get quietly rerouted elsewhere?
You can technically "deliver" an email and still lose if it lands in spam. Sender reputation, authentication, content, and recipient engagement all factor in.
It's a bit like a courier dropping a package at the front desk of an office building. Getting through the door isn't the same as reaching the right person's hands.
7 Common Email Deliverability Problems and How to Solve Them
Below is a list of common problems regarding email deliverability and potential solutions. The issues are listed in the approximate order of importance.
1. Poor Sender Reputation
If deliverability is the problem, the first thing to check is sender reputation, the cumulative perception of your domain or email address formed by mailbox providers.
A poor sender reputation can be the result of complaint spam, hard bounces, or other negative signals.
Even if you believe that your messages are harmless, a sufficiently negative opinion from any mailbox provider will result in your emails being rejected or placed directly into the spam/junk folder.
The good news is that you typically don’t need to completely rebuild your reputation from scratch to solve the problem.
Reduce the complaint rate by only sending messages to those who have subscribed to your emails, lower the overall bounce rate by cleaning your email list, and avoid sudden increases in volume or daily sending limits.
2. High Email Bounce Rates
Email bounces are another factor that adversely affects sender reputation. Both soft and hard bounces should be treated as potential issues, with the latter being more important.
In many cases, poor deliverability results from sending emails to invalid, inactive, or otherwise erroneous addresses. This problem has a simple solution – remove such email addresses from your list.
You can also minimize the impact of poor-quality leads on the overall bounce rate by only sending to addresses that you know to be valid. Lastly, keep an eye on the bounce rate and examine individual cases to identify and eliminate the causes of repeated bouncing.
3. Missing or Incorrect SPF, DKIM, and DMARC Records
SPF, DKIM, and DKIM/IMARC records are used by recipients to verify that an email is not falsified, forged, or redirected. As such, improper configuration will invariably result in poor email deliverability.
The best approach to this problem is to check that the appropriate records are in place, configure them correctly, and, most importantly, not use the same domain for large-scale sending without first letting mailbox providers know that you are doing so.
If you don’t know where to begin, here’s a helpful DMARC generator that will allow you to quickly and easily configure your own DMARC policy.
4. Sending Too Many Emails Too Quickly
Sending volumes that are suddenly higher than average are usually an adverse sign. Volumetric attacks are a known concept in cybersecurity, and mailbox servers rightfully treat large amounts of data sent by a single email server as a potential threat.
If you intend to send more messages than usual, the best way to avoid deliverability problems is to avoid sudden volume increases.
5. New Email Accounts or Domains Without a Warm-up Process
Newly created email accounts and domains do not have a reputation history, which causes them to be flagged as spam automatically.
Use of these for regular, large-scale sending will invariably lead to poor deliverability outcomes, as mailbox providers will assume that you are doing test runs.
A quick fix for this is to invest some time into preparing the account following best practices for warming up a new email account. This will not always result in immediate improvements, but it should still give your new emails a much-needed boost.
Anyone setting up new mailboxes for ongoing outbound work can take a look at email warmer, which walks through how the process works.
6. Poor Quality or Outdated Email Lists
Finally, poor email list hygiene will almost always result in deliverability problems. This is caused by a combination of factors, such as emailing inactive users, sending too many messages, and purchasing lists with poor-quality leads.
To avoid problems with deliverability, make sure that your emails are only sent to active users who have opted in to receiving messages.
Regularly clean your list to remove inactive users, and try to avoid buying email lists from external resources, as these are often full of invalid addresses.
As a result of these issues, emails sent to inactive users will be placed into the spam folder more frequently. By limiting messages to active users and only sending them when absolutely necessary, you can prevent this from adversely affecting your email metrics.
7. Spam Filters Triggered by Poor Email Content
Your spam rate is strongly linked to poor email content. While subjects containing clickbait or spammy language, a high sales pitch, and other questionable elements will often trigger spam filters, resulting in worse deliverability outcomes.
To fix this issue, write subject lines that clearly indicate the contents of the attached message. Additionally, avoid using spam triggers in your email content. A careful examination of sender reputation, SPF/DKIM/DMARC records, list quality, email volumes, and email content checker will allow you to determine the cause of the problem with few issues. Where possible, make your emails more personal, less salesy, and easy to use on mobile devices.
As an alternative to trial-and-error, you can send your email to a small sample group and check whether any spam triggers were activated.
Final Considerations on Email Deliverability Solutions
To recap, almost all issues regarding poor deliverability can be traced back to a limited set of causes.
Spam filters and mailbox servers will typically disregard messages that fail standard authentication checks (SPF, DKIM, DMARC), originate from untrusted, new domains, or simply contain too much content at once.
If you know what causes your deliverability issues, fixing them is as simple as cross-checking your current configuration against the recommendations provided above and making adjustments as needed.
A useful course of action when troubleshooting deliverability problems is to examine your bounces and determine the nature of the issue. If your messages are frequently rejected, look into whether SPF, DKIM, or DMARC records are misconfigured or missing.
From there, examine the bounce rate and complaints, followed by sender reputation, list quality, email volumes, and content - in this order. It will usually allow you to isolate the cause of the problem quickly and easily.
Conclusion
Most issues that negatively impact deliverability and inbox placement can be resolved with relative ease.
From there, you can follow the recommendations provided above to resolve this or seek further assistance if needed.
Do not forget that these are not static properties that can be set up and forgotten. Instead, they require ongoing maintenance and adjustment to obtain the best possible results.
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