How proper warm-up improves email deliverability and boosts results

In this case study, we will dive into the importance of warm-up in email deliverability and how it positively impacted the results of a client who partnered with our SMTP solution. By implementing a systematic warm-up process, our client witnessed significant improvements in their email deliverability rates, resulting in higher engagement and better campaign outcomes, but most important they managed to build a good reputation for the IPs used ensuring this way high performance for long term.

But first, a quick overview of what is the warm-up process and why is so important for your success. The warm-up process is essential for building a solid sender reputation, increasing email deliverability rates, and delivering effective campaign outcomes. 

The steady and methodical process of building a good sending reputation for a new IP address or domain used for sending emails is known as the warm-up process. To prove to Internet Service Providers (ISPs) and mailbox providers that the sender is reliable and committed to delivering legitimate, non-spammy emails, it entails progressively increasing the volume and frequency of emails sent over a certain period.

Embracing the warm-up process demonstrates a commitment to responsible email practices and helps build trust with ISPs, ultimately leading to improved results and a stronger email marketing strategy.


Meet Outreach Solutions Media

Outreach Solutions Media, a growing company, founded in 2019, that helps small businesses properly monetise their email lists in various industries, was experiencing challenges with their email marketing efforts and inboxing rates. 

Despite having a high-quality email list and well-crafted content, they were struggling with low deliverability rates and and implicitly with low engagement rate, clicks and opens. 

After a thorough analysis, they decided to give a chance to Inboxroad’s infrastructure and expertise since they realised how important it was to improve their email deliverability.


Challenges faced

Prior to working with Inboxroad and our team of specialists, our client encountered various challenges that hindered their email deliverability and success. These challenges included:

  • Low inbox placement rates: The client’s emails were often routed to recipients’ spam folders or blocked entirely, significantly reducing their chances of being seen and engaged with.


  • High bounce rates: The client’s campaign success was significantly impacted by the number of emails that were returned as undeliverable due to invalid or inactive email addresses.


  • Poor reputation of IPs and damage to sending domains: Without the proper guidance and warm-up, building a good reputation was problematic.  All delivery metrics failed to indicate success because the sending practices not only affected the IPs utilized but also the domains used.


Solution proposed: Starting clean with a new sending strategy and fresh infrastructure


Understanding the importance of a proper warm-up process, Inboxroad’s team worked closely with the client to design and implement a comprehensive warm-up and scaling strategy. 

First, for the warm-up process we followed the next 3 key steps:

  • Gradual Volume Increase: Initially, the client started with a small volume of emails and gradually increased the volume day by day, slowly reaching the desired daily volume in a safely manner. This allowed the client to establish a positive sending reputation with ISPs and mailbox providers.


  • Controlled Sending Frequency: To prevent overloading the ISPs, the sending frequency was limited as well during the warm-up procedure. The client made sure that the transition went well while establishing confidence and trust by gradually increasing the frequency.


  • Monitoring and Adjustments: Our team carefully analyzed important indicators throughout the warm-up phase, including bounce rates, complaint rates, and overall delivery performance. As a result, we were able to optimize the warm-up approach in accordance with the obtained data.



The results, in terms of email deliverability, of the client’s campaign were significantly improved once the warm-up process was put in place. The effects that were seen were the following: 


  • Higher inboxing rates: The client’s inbox placement rates significantly increased as a result of the progressive warm-up procedure. Emails that had previously ended up in spam folders started making their way to the main inbox, increasing their visibility and likelihood of being opened.


  • Decreased bounce rates: The client was able to drastically lower their bounce rates thanks to the warm-up process. The result suggested a more precise and clean email list, enabling them to contact actual recipients.


  • Increased Open and Click-through Rates: The customer saw a spike in open and click-through rates as a result of increased deliverability. Their messages were now successfully reaching the intended audience, resulting in higher engagement and increased website traffic.


Outreach Solutions Media’s email performance improved drastically. Delivery rate is now at 98.8% with a major decrease of bounce rate to 0.2%. We, at Inboxroad, continue to assist during the entire partnership through weekly performance reports and advice from our specialists, continuous monitoring and optimisation of infrastructure and strategy.


*Results for April 2023


“We use Sendgrid as well but they lack support when it is needed at times. With Inboxroad there has always been a fairly quick response to any questions or concerns we may have even on weekends.  Also you guys always have suggestions when deliverability issues may occur. So overall performance tends to be better compared to Sendgrid, due to your support. Suggestions such as having patience with warming up and following the warm up schedule properly was also a major factor in our success.” – Tray Stinson, Outreach Solutions Media

This case study is looking to highlight the importance of a systematic warm-up process in improving email deliverability and subsequently boosting campaign results. By partnering with Inboxroad and implementing a carefully designed warm-up strategy, our client overcame their email deliverability challenges and witnessed remarkable improvements in engagement and campaign performance.

We strongly advice for a proper warm-up strategy for any business striving to achieve optimal email deliverability. This process establishes a positive sender reputation, reduces bounce rates, and increases inboxing rates, ultimately leading to higher engagement. 


Want to get the best results out of your campaigns and increase delivery rate?

Reach out today and our team of specialists will be more than happy to help you achieve your goals!