Addressing why your emails are not being opened is a complex topic, as several factors must be considered.
If you're experiencing a low open rate, there are some common reasons this may be happening and a few actions you can take that may help.
Where to check your open rate
You'll find your open rate in a few places:
The Statistics tab within a sequence, for a more detailed breakdown
The Engagement section, for unique opens per recipient across all steps
The Reporting section, for filtering and exporting data across sequences
Your emails bounced
Make sure you always verify your emails and use emails with a Valid status. Learn more on how to verify emails in Hunter here.
If you receive a bounce message, it should give you an indication of why your email bounced and wasn’t delivered. This can help you understand what happened and decide how to proceed.
For example, if the bounce message says the email address doesn’t exist, it usually means the recipient address is invalid or no longer active. In that case, it’s best not to contact that address again.
While we don’t recommend including Accept-all emails in your sequences, as they can’t be verified, you may consider adding a small number of accept-all emails with a high confidence score.
To learn more, we recommend reading our guide on how to handle accept-all emails here.
The emails weren't delivered to the main inbox
Your email may have been blocked from delivery entirely (this can happen even without a bounce message), or it may have landed in spam due to an automatic filter block. Both are usually caused by low sender reputation or missing email authentication.
Some ways to address this are:
Implement email authentication protocols
Monitor email blocklists
Manually Warm up your domain and your inbox before sending more emails
Use Progressive sending to slowly but automatically warm up in Hunter
Purchase Inbox protection (paid add on for paid plans)
Don't send emails to multiple recipients from the same company
💡 Note that Progressive sending and Inbox protection, work differently and can't run at the same time on the same account — Inbox Protection already includes progressive volume increases as part of its warm-up.
The subject line didn't resonate with your audience.
This depends on your sequence, offer, and audience, so there's no one-size-fits-all fix — but these guides can help:
Monitor your sender health over time
Deliverability isn't a one-time fix — it's worth checking regularly. The Global Health score in the Email Account Center gives each connected account and domain a score out of 100, based on checks like SPF/DKIM/DMARC configuration, blacklist status, domain age, and sending activity.
The Deliverability Guard panel shows exactly what's affecting your score and links to the fix for each issue — it's the fastest way to catch a reputation problem before it starts hurting your open rate.
If you have questions after reviewing the above resources, don't hesitate to reach out via chat or email contact@hunter.io, and we’d be happy to help.