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How Folderly Saved Sujo From the Outcome of a Domain Switch Gone Wrong

Warm Email Marketing
Open Rate
Email Deliverability
Daniel Rendon
CEO at Sujo

This case holds a special place in our hearts because it was the first time Folderly tools were used to remedy severe deliverability issues. It is also a very informative illustration of how important it is to warm up your new domain before you use it as the main domain for your email marketing activities. 

The client, SUJO.app, is a news platform that serves as an alternative to social media and other information sources. With SUJO.app, users can receive newsletters and read verified facts about events and occurrences all around the world. Naturally, email marketing played a major role in SUJO's performance, generating daily active users (DAU) and expanding the database of users. 

For the SUJO team, it was necessary to keep up the pace, improve the conditions for users and implement new features. Once the DAU grew to 12,000 users, SUJO decided to rebrand the platform by moving to a new .app domain and continuing to send newsletters to subscribers from there. This is where the client discovered all changes required thorough preparations - and good domain analysis tools.

Breaking point 

1. Drop in email deliverability. Even though the process of domain switch was seemingly smooth and friction-free, the aftermath soon emerged in the shape of the following metrics:

The decline in performance was a reason for concern - it meant that fewer users could see SUJO newsletters in their inboxes and didn’t interact with the links to new articles.  

These negative changes occurred within a month. As more time passed, the metrics kept going down. Two more weeks later, it wasn't only the newsletters that were barred access to the recipients' inboxes. Payment recipes, invoices, and other kinds of transactional emails sent by SUJO were never seen by subscribers. This was another indicator of serious issues triggered by the domain switch. 

2. Loss of subscribers. The month of reduced mailbox invisibility had an impact on SUJO's subscribers. Having started their switch at an impressive number (12,000 subscribers), SUJO had only 500 subscribed readers remaining by the end of the month. As a consequence, the reduced user activity and low engagement rate took their toll on the client's Sender Score.


1. Research. Folderly ran a domain analysis of the client’s new domain and mailboxes to see their average health, evaluate SUJO’s current sender reputation, and find the root of the problem.

The research revealed that the most glaring and heavy issue was in plain sight: the client used the newly registered Outlook domain to launch newsletter campaigns to 12,000 subscribers without going through the obligatory warmup process. It triggered a negative response from internet service providers and email services. 

The lack of warm-up put spam filters and email service providers on high alert. As they kept seeing a large number of messages coming from a fresh domain, they started treating this activity with suspicion, barring access to the recipients’ inboxes.

2. Troubleshooting. Once we discovered the reason behind the drip in deliverability, it was time to devise a strategy for restoring SUJO’s DAU and bringing its good reputation back. 

    • Migration to a new Gmail domain. The state of the new domain’s reputation was too compromised, so it made little sense to try and restore it. Focusing on creating and warming up another new domain was the wisest and the most effective strategy. This step was handled by the team of Belkins that managed and overviewed the entire process.

    • Gmail domain registration. Belkins team registered the new domain for SUJO and checked its DNS records using Folderly. All necessary email authentication protocols are usually generated by Gmail and they’re more than enough to resist spoofing attempts and guarantee the security of mailbox users. However, when it comes to editing DNS records to particular email marketing needs, some adjustments are required.
    • Mailbox setup. Next, Belkins created and fine-tuned new mailboxes and verified them with MailChimp, while Folderly ensured monitoring of each mailbox.
    • Warmup campaigns. Belkins' experts started sending small batches of emails to engaged email addresses, checking recipient engagement rate and CTOR/CTR ratio. At this stage, Folderly was used for viewing the open rate and the Sender Score of the new domain.

    • Mailbox discipline. The final step was making mailbox monitoring and domain health analysis a habit for the client. With the toolset of Folderly, the client was able to check their new inboxes and test their performance. Also, the SUJO team was able to get instant notifications about any budding issues or a drop in performance, which meant that they would never be caught by surprise due to a sudden change in deliverability.


Campaign performance restored. After shutting down the Outlook domain and using the warmed-up G Suite domain for email campaigns, we were able to increase the click-to-open rate and click-through rate and make them as productive and dynamic as they were before the switch.

  • Subscribers recovered. The new G Suite domain was able to reach the client's subscribers, informing them about the issues that the SUJO platform experienced and remarketing them. Ultimately, the client's DAU went back to 12,000.
  • The engagement rate increased. Warmup campaigns bore fruit by generating more interactions and creating a solid engagement rate that made email service providers prioritize clients' emails over other incoming messages. At the end of our work, the average engagement rate for SUJO grew up to 90%.
  • Deliverability maximized. Due to improved inbox visibility and the engagement rate boost, the overall deliverability went up to an impressive 100%. It became a great advantage for the client, who intended to keep increasing the number of subscribers.

Key takeaways

  • Always create a new domain per direction. It's generally advised not to mix your campaigns. You must send your newsletter campaigns from one subdomain, transactional emails from another subdomain, and keep an entirely new domain for any experimental email campaigns you have in mind. It will make sure that your transactional emails won't be affected by the reputation of your newsletter images, and vice versa.
  • Never ignore domain warmup. Make sure to launch warmup campaigns for every new domain that you create and use for your email marketing activities. Especially if you plan to shift your client-generating efforts to a new center of operations - you will be interacting with your loyal database and will need to send a huge amount of emails. 
  • Reach out to your audience. When you're planning a domain switch, warn your recipients. Sending an email saying that you will be performing from a new domain from now on and asking them to interact with your new @gmail.com emails will let you keep your engagement at its current level and grow. 
  • Monitor your performance regularly. Every change you make needs thorough monitoring. It's extremely important to equip yourself with a reliable system that can provide you with tools for analysis, data tracking, and reporting. With your KPIs and Sender Score in full view, you can rest assured that everything is going according to the plan and stay aware of any potential threats coming your way.
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