Email reputation best practices

Your sending reputation dictates whether your emails are seen by recipients. Follow this list of best practices to build and maintain a healthy sending reputation.

Have a clear Opt-In process for new email recipients

Sending emails to people who have not provided clear permission to be emailed often leads to emails being reported as spam, which actively harms your sending reputaiton.

Collecting the email as part of your sign up process or account creation is not enough. Consent needs to be explicitly given.

Opt-in Check Box

At minimum, include a checkbox asking for permission to send emails.

Implement a “Confirmed Opt-in” or “Double Opt-in”

A confirmed or double opt-in process requires the recipient to confirm their interest by clicking a link in a confirmation email. This method:

• Increases engagement
• Verifies compliance (e.g. GDPR, CAN-SPAM)
• Filters out fake or mistyped addresses
• Reduces complaint and bounce rates
• Prevents abuse and list bombing

Learn how to create a Confirmed Opt-in Journey.

1. Create an `initial_opt_in` tag

   Add an initial_opt_in tag with a value of true for newly added or imported email subscriptions.

2. Create an Initial Opt-in segment

   Create a segment called Initial Opt-in using the initial_opt_in tag.

   

   Initial Opt-in Segment
3. Create a Confirmed Opt-in email template

   Create an email template with a single “Confirm” button or link.

   
4. Create a Confirmed Opt-in Journey

   Build a Journey that starts with the Initial Opt-in segment and immediately sends the confirmation email.

   

   Confirmed Opt-in Journey Send
5. Add a Wait Node and Yes/No Branch

   Add a 15-minute Wait node followed by a Yes/No branch to check if the confirmation link was clicked.

   

   Wait Node and Yes/No Branch
6. Tag users who confirm

   Tag users who clicked the confirmation link with confirmed_opt_in = true.

   

   Confirmed_opt_in Tag in Journey
7. Add additional follow-ups

   Add Wait nodes and Yes/No branches to retry confirmation over several days.

   

   Check for Confirmed Opt-in at Intervals

You now have email subscribers with a confirmed_opt_in tag that you can use to create segments.

Offer email preferences

Let users choose what types of emails they want—Newsletters, Rewards, Deals, Product updates, etc.

Email preference center

Make it easy for users to adjust these preferences anytime via an email preference center.

---

Monitor spam reports and complaints

Unchecked spam reports can quickly destroy your sending reputation. Monitor them closely—more often than open or click rates.

You can view Spam Reports in the Audience Activity section of each message and in your Suppression List.

Consider why users might report your emails as spam:

• Did they disengage over time?
• Did they knowingly opt in?
• Were they sent too many emails?
• Was the content aligned with their expectations?

Use Google Postmaster Tools

Gmail is the largest inbox provider. If you’re seeing issues with Gmail, you’re likely having issues elsewhere too.

Google Postmaster Tools gives insights like domain reputation and spam rates from Gmail users.

Gmail does not provide per-user spam reports. Only aggregate spam rate data is available through Google Postmaster Tools.

Google Postmaster Tools

Learn how to set up Google Postmaster Tools.

---

Target engaged recipients

Inbox providers reward high engagement. Recipients who open and click are more likely to receive future emails.

• Use Yes/No branches in Journeys to send follow-ups based on open/click behavior.
• Stream email events to your data warehouse or CRM for analysis.

Email Opened Yes/No Branch

Exclude or sunset unengaged recipients

Low open rates indicate poor engagement and hurt your reputation.

Implement a sunset policy to remove users who haven’t opened or clicked emails in 2–3 months (depending on your send frequency).

---

Do not send excessive emails

Sending too many emails increases the risk of unsubscribes and spam complaints.

Evaluate frequency from the recipient’s perspective. Daily emails may be too much.

• Use Wait Nodes and Yes/No branches to manage frequency based on engagement.

What NOT To Do

---

Deliver value, not just promotions

Every email should provide real value—insights, tips, solutions, or relevant updates.

A discount code alone does not equal value.

Evaluate content performance

Your audience expects specific content types. Make sure you’re meeting those expectations.

• Use multi-link tracking to learn what content is most clicked.
• Run A/B tests to see what resonates.

Use email to build relationships and get feedback

Email is a conversation channel—not a billboard. Use it to build trust and invite responses.

Replies actually help your sending reputation.

Use a valid reply-to address. Avoid “no-reply” emails.

---

Ensure proper warm-up

Inbox providers may block high-volume email sends from domains with no sending history.

If you’re sending large volumes—especially from a new domain or provider—gradually increase volume to build trust.

Learn more about Warm Up and how to use OneSignal’s Auto Warm Up.

---

Avoid invalid emails

High bounce rates hurt your reputation and indicate poor list hygiene.

Use Confirmed Opt-in to prevent invalid emails.

Before importing, clean your list by removing:

• Obvious typos like @gnail.com, @yagoo.com
• Incomplete or malformed emails like someone@.com

If migrating from another platform, use its Suppression List to avoid importing known bad addresses. You can also delete users or upload a Suppression List.

Email verification tools

Validation tools can help detect invalid or risky addresses before import:

• Kickbox
• ZeroBounce
• NeverBounce
• BriteVerify
• Mailgun

After validation, follow our import guide to upload clean, verified lists.

---