Email Warm-up

Why Warm-up?

Warmup is done to ease inboxing process and establish a positive sending reputation with ISPs. It is essential when you are planning to use a new, dedicated IP address/domain through which large volumes of emails are to be deployed. This strategy is designed to set you apart from spammers and let ISPs know the type mailing you are doing.

Warm-up helps build sender reputation:

Good reputation = Inbox
Bad reputation = Spam/Blocks

When a new client is on-boarded and ready to start their mailing activity, warm-up becomes the most important factor. It not only helps build the IP and domain reputation but also helps determine that the mails are genuine. Warm-up also helps gain a wide view about other important factors such as client engagement and data quality. It helps build a strategy that directly helps build the performance for future campaigns.

Elements of Warm-up

The various factors that need to be considered for Warm-up is as follows

Understand the Business and Marketing strategy

Every client has a different business model based on which the marketing strategy varies. The requirements of each of these clients are different. With respect to emailing, the two major types are : Promotional and Transactional.

  • Promotional: Clients that have an e-commerce platform usually send a huge volume of emails. The emails are mostly promotional emails and also transactional. It is important to understand the kind of business and the marketing strategy. This gives an idea about the data to be targeted which in turn helps forecast the performance.
  • Transactional: Transactional emails are always genuine emails that get triggered based on user activity. This is mainly used by banking clients.


The setup is very important when it comes to inboxing. The set-up can be either dedicated or shared. Apart from this, the link tracking URL, image hosting URL, footer , SPF, DKIM and DMARC records play a major role in delivering emails to Inbox.


Once a client is on-boarded, it is important to understand the quality of data. A little research on how the genuine the data is, becomes must. For this, it is essential to determine how the data has been gathered. There are various methods using which the data is collected. The best process that most of the online portals use now-a-days is the Signup process. The clients signup and create an account on the online portal. However, we can still question whether or not the data is genuine as long as double opt-in sign up is in place. Double opt-in is when an email ID is verified to be genuine. Either a verification mail is sent to the email ID entered or the email ID is asked to be entered twice and confirmed.

The data can also be collected offline through surveys or using feedback forms. But the data cannot be relied upon as there is no way in which we can verify if the IDs are genuine. Once the data to be targeted is determined, the warm-up can be initiated. However, post this the real challenges are encountered. Using the best data but not being able to attain user-engagement is a major concern. In order to build the reputation, it is important to have user-engagement. Whether or not the email is opened, if the client has clicked on the creative and visited the landing page and if the client has marked the email as favourite, are some other factors that help inbox deliverability. When the email lands in the correct box there are high chances of attaining user engagement.

Apart from this, it is also important to gather blacklisted data (unsubscribed users) so we can avoid sending emails to such clients.

Segmentation of Data

Data segmentation also helps build the reputation of a set-up. Data can be segmented as openers, clickers and recent subscribers. When warm-up is initiated, we can begin with the most active data-set, which is openers and clickers and then we can move on to the subscribers data. This can be further segmented into 0-30 days subscribers, 30-60 days subscribers and 60-90 days subscribers for better results.

Guidelines to be followed

  • Always ensure that there is an unsubscribe footer
  • Always check the content and remove alt tags, title tags, commented codes and javascript
  • Creative warm-up is necessary
  • The creative and its structure holds 20% of importance when it comes to getting good inboxing
  • Starting with single image creatives paves an easy warm up path
  • The reputation of domain and IP always needs to be monitored
  • Always sign DKIM on the sender domain
  • Always start with the most active data-set
  • Monitor the open rates as this ensures if the data targeted is good data or not and if it helps attain user-engagement
  • Try targeting different data at different times to find the optimum time for each list