Email deliverability is your ability to get emails into your recipients’ inboxes rather than their spam folders.

Deliverability depends on several factors, including your sending reputation, contact list quality, message content, and sending frequency. One of the best ways to monitor deliverability is to track the performance of your emails over time, especially your open rate, bounce rate, and unsubscribe rate.

These metrics help you understand how recipients interact with your emails and whether your sending practices are healthy.

What affects email deliverability?

Even if your email is technically sent successfully, that does not always mean it will reach the inbox. Deliverability can be influenced by:

• Sender reputation, including your IP reputation
• Contact list quality
• Email design and content
• Sending frequency and relevance

Reviewing your key email metrics regularly helps you identify issues early and improve your long-term performance.

Open rate

Your open rate measures the percentage of delivered emails that were opened by recipients.

It is calculated by dividing the number of opened emails by the number of delivered emails.

What is a normal open rate?

• Marketing emails: typically between 15% and 25%
• Transactional emails: typically between 30% and 40%

Transactional emails usually perform better because recipients are expecting them, such as password reset emails, order confirmations, or account-related notifications.

Why open rates vary

Open rates can differ significantly depending on your industry, audience, and message type. Some sectors naturally see higher engagement, while others tend to have lower averages.

Bounce rate

Your bounce rate shows the percentage of emails that could not be delivered to recipients.

A bounced email is an email that returns with an error instead of reaching the recipient. This can happen for several reasons, such as invalid email addresses, closed inboxes, or outdated contacts.

What is an acceptable bounce rate?

Your bounce rate should be kept as low as possible, ideally close to 0%.

As a general rule, your bounce rate should remain below 5%. If it rises above that level, your account may be reviewed or temporarily suspended.

How to reduce your bounce rate

1. Use double opt-in
   Double opt-in helps ensure that only valid and intentional sign-ups are added to your list.
2. Clean your contact lists
   Remove invalid, old, or inactive contacts regularly.
3. Send regularly
   Sending at least once per month helps keep your list active and reduces the risk of sending to abandoned or outdated addresses. 

Unsubscribe rate

Your unsubscribe rate measures the percentage of recipients who choose to opt out after receiving your email.

What is a good unsubscribe rate?

In general, an unsubscribe rate below 1% is considered normal.

• 0% to 0.5%: excellent
• 0.5% to 1%: acceptable
• Above 1%: needs attention

Why recipients unsubscribe

Common reasons include:

• They do not remember signing up
• Your emails are not relevant to them anymore
• You send too often or not often enough
• Your content no longer matches their expectations

How to keep unsubscribe rates low

1. Build a quality contact list
   Send only to recipients who explicitly opted in.
2. Find the right sending frequency
   Stay visible without overwhelming your audience.
3. Send relevant content
   Personalize and segment your emails where possible.
4. Provide value
   Make sure your emails contain content, updates, or offers that recipients actually want.
5. Keep the unsubscribe link visible
   Making it easy to opt out helps reduce frustration and can prevent spam complaints.

How to use these metrics together

Looking at one metric in isolation does not give the full picture. The best way to assess deliverability is to review your metrics together:

• Low open rate may point to inbox placement issues, weak subject lines, or low audience engagement.
• High bounce rate often signals poor list hygiene or outdated contact data.
• High unsubscribe rate usually means your content, frequency, or targeting needs adjustment.

Monitoring these indicators over time will help you detect issues early and improve both engagement and deliverability.

Best practices to improve deliverability

• Use high-quality, permission-based contact lists
• Prefer double opt-in when possible
• Send regularly to keep your audience engaged
• Clean your lists and remove outdated contacts
• Make your content relevant and valuable
• Maintain a clear and visible unsubscribe option
• Review your email metrics after each campaign