# Build a suppression list for better deliverability

Day 1 - Email Performance Audit  
Day 2 - Email Authentication  
Day 3 - Domain Reputation  
Day 4 - Domain/IP Blacklist  
Day 5 - Seed List  
Day 6 - Domain Warm-up  
Day 7 - Preference Center  
Day 8 - Suppression List  
Day 9 - Engagement-based Segmentation  
Day 10 - Segmentation for personalization  
Day 11 - Sunset Policy  
Day 12 - Send Time Optimization  
Day 13 - Email Schedule  
Day 14 - Template Audit  
Day 15 - Dark Mode Audit  
Day 16 - Email Responsiveness Audit  
Day 17 - Collect Subscriber Feedback  
Day 18 - Email CTA  
Day 19 - Email Footer  
Day 20 - Subject Line Performance  
Day 21 - Webinar

### What will this help with?

- Better domain reputation and deliverability
- Have a healthy email list with only valid, consenting, and active email ids

### What is a suppression list?

A suppression list contains all the email addresses that have opted out/unsubscribed from a company’s emails to prevent sending emails to them in the future. Generally, a suppression list might get updated with hard-bounced email ids as well to avoid sending emails to them.

### How to create a suppression list?

1. Export all contact data along with subscription and bounce details from your email service provider.
2. Separate email IDs that have unsubscribed or hard bounced into a list.
3. Verify the remaining emails using services like Bouncer, ZeroBounce, NeverBounce, etc. These will help you remove invalid, non-existent, and spam-trap email ids.
4. Collect all the invalid email ids from Step 3 and add them to the list from Step 2. This list is your suppression list.
5. Remove the email ids in the suppression list from your contacts database. Usually this can be done using features for importing suppression lists.
6. Remember not to send emails to the email ids in the suppression list.

#### 💡 Resources

- [How to Verify Email Address and Clean Email Lists](https://www.mailmodo.com/guides/clean-email-list/)
- [What is a Suppression List And Which Email Addresses to Add](https://www.mailmodo.com/guides/suppression-list/)

### How to use the automatic suppression list feature in Mailmodo?

With Mailmodo, every time a contact hard bounces or unsubscribes from a particular campaign, they are automatically added to the suppression list.

If you want already have an external suppression list, then you can upload them in Mailmodo and avoid sending emails to them. Read this [document](https://support.mailmodo.com/articles/749237-how-to-upload-suppression-list-in-mailmodo) to learn how to upload the suppression list in Mailmodo.

### Tips and best practices

- Set a schedule to clean your list regularly. This can be monthly, quarterly, or after every campaign, depending on your convenience.
- Use a [double opt-in](https://www.mailmodo.com/guides/double-opt-in/) process to ensure the subscriber truly wants your emails.

**What you should do next**

Hey there, thanks for reading till the end. What now?

1. **Complete the task with Mailmodo**  Take action and complete the task to improve your email performance using Mailmodo. [Try it for free for 21 days](https://manage.mailmodo.com/auth/signup?utm_source=21-day-challenge&utm_medium=internal-page).
2. **Join the challenge** If you want to get daily emails with actionable tasks with step-by-step instructions to stay motivated to improve your email performance then [register for the the challenge here](https://www.mailmodo.com/email-challenge/).
3. **Need some help?** If you have any questions about the task, ask us on our Slack community and get answers from experts. [Join the community here](https://join.slack.com/t/marketing-tribe/shared_invite/zt-1fn53vac0-QvZB4BvbEu5L7AzzNCl9xQ).

## Take the 21 Day Email Performance Challenge

In association with

Samar Owais

Email Strategist and

Conversion Copywriter

Start now