Examples of Positive and Negative Feedback Loops in Email Deliverability

Feedback Loop (FBLs) are systems used to collect user engagement data, and utilize it to influence email filtering decisions. Each mailbox provider — such as Gmail, Yahoo and Outlook — have a developed feedback loop that can cater to their users. 

It is intended for mailbox providers to improve their spam filtering algorithms, and improve better user experience for email recipients. 

Feedback loops are determined under two classifications:

• Positive feedback loops improve a sender’s reputation by reinforcing good email practices, such as high open rates and user engagement.
• Negative feedback loops degrade a sender’s reputation when recipients mark emails as spam or fail to engage with the content.

Understanding and managing these feedback loops are one of the best practices to maintain high email deliverability and inbox placement rates.

Examples of Positive Feedback Loops in Email Deliverability

Engagement-Based Inbox Prioritization

Mailbox providers monitor how users interact with emails. Actions like opening emails, replying, moving emails to specific folders, or marking them as important signal positive engagement.

Example:

A SaaS company sends a personalized onboarding sequence to new users. Because the emails contain relevant tips and solutions, recipients open them, click on helpful links, and reply with questions. Over time, mailbox providers recognize that emails from this sender are valuable, prioritizing them in users’ inboxes instead of promotions or spam folders.

Best Practices:

• Send relevant, personalized content tailored to user interests.
• Optimize subject lines to encourage higher open rates.
• Use segmentation to target engaged users with the right messaging.

Users Moving Emails from Spam to Inbox

Some recipients will move an email from spam folder to their inbox, by either reporting as “Not as Spam” — the process may vary depending on the email service provider — sending signals to mailbox providers that the email is most likely legitimate and should not be under spam. This contributes to improving an email’s reputation and will be counted as a positive feedback loop. 

Example:

An e-commerce brand sends order confirmation emails that sometimes end up in spam. However, customers who actively look for these emails in their spam folder and move them to their inbox send a positive signal to email providers, improving future email placements.

Best Practices:

• Encourage recipients to add your sender address to their contact list.
• Educate users on how to whitelist your emails.
• Send transactional emails with clear branding and valuable information.

3. Increased Reply and Forward Rates

Email replies and forwards indicate user interest and engagement, signaling a positive sender reputation.

Example:

A B2B company running a sales outreach campaign notices that prospects frequently reply to emails and forward them to colleagues. This activity helps mailbox providers classify these emails as valuable, increasing deliverability for future campaigns.

Best Practices:

• Write conversational email content that encourages replies.
• Include questions or prompts to spark engagement.
• Use email signatures with contact details to make replies easy.

Examples of Negative Feedback Loops in Email Deliverability

Spam Complaints

When recipients mark an email as spam, mailbox providers use this data to classify future emails from the sender as junk mail, hurting sender reputation.

Example:

An online retailer aggressively sends promotional emails without proper list segmentation. Many recipients find the emails irrelevant and mark them as spam. Over time, mailbox providers identify this sender as a potential spammer, causing future emails to be blocked or sent directly to the spam folder.

Best Practices:

• Use double opt-in to ensure recipients genuinely want to receive emails.
• Honor unsubscribe requests promptly.
• Reduce email frequency for disengaged users.

High Bounce Rates

Emails sent to invalid or inactive email addresses result in hard bounces. Mailbox providers interpret high bounce rates as a sign of poor email list hygiene, leading to a negative feedback loop.

Example:

A startup purchases an email list and starts a mass cold email campaign. Many emails bounce due to invalid addresses, and the sender’s domain is flagged for poor list management, reducing deliverability for future campaigns.

Best Practices:

• Regularly clean email lists to remove invalid addresses.
• Use an email validation tool before sending campaigns.
• Monitor bounce rates and take corrective actions.

Low Open and Click Rates

If recipients consistently ignore or delete emails without opening them, mailbox providers interpret this as a lack of interest, negatively affecting the sender’s reputation.

Example:

A software company sends weekly newsletters to its entire list, including inactive users. Over time, open rates decline, and mailbox providers categorize these emails as low-priority, leading to poor inbox placement.

Best Practices:

• Use engagement-based segmentation to send emails to active users.
• A/B test subject lines and content to improve open rates.
• Remove or re-engage inactive subscribers.

How to Manage and Improve Feedback Loops with Warmy.io

As an all-in-one email deliverability tool, we understand the immense contribution of FBL for understanding your email reputation. Acquiring a positive feedback loop is every email marketers goal. Besides subscribing to the FBL services one of the factors that can help you manage and attain a positive feedback loop is having a reputable domain. Warmy has a variety of features for improving your email deliverability and obtaining positive feedback loops. 

Free Email Deliverability Test

Warmy is renowned for its free email deliverability test. Using this can help you understand any potential issues with your domain that can cause significant damage to your deliverability.