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E-mail Marketing - Trust with a Solid Warm-up Plan

20 min read


Become a trusted e-mail sender with a solid warm-up plan

Trust is the currency within e-mail marketing. In this article, we will show you how you can build up trust with a solid warm-up plan. We will define why and when a warm-up is needed and how to build a plan that is tailored to your individual needs.

Table of Contents


image one: construct of trust

Despite all the great new channels, tactics, and technology, e-mail marketing remains one of the main campaign tactics used in most countries around the globe. However, it is often an underestimated channel leading to inefficient usage.

In the article Welcome to E-mail Marketing, we have already introduced you to the essentials of e-mail marketing and took you on a journey to become a deliverability hero.

Now, it is time for your next step in your journey to learn how to become a trusted sender. Trust is a key factor when it comes to communication. Regardless of the channel, you tend to give attention to those who you consider reliable and trustworthy. The same occurs with e-mail campaigns. You are joining a limited and controlled territory so you must be sufficiently reliable to not only be allowed to enter this territory, but also to receive attention from people. Being a trusted sender requires you to comply with industry standards around message authentication and domain setup, as we have explained in the article E-mail Marketing - Trust with the Right ESP Setup.

In addition to the technical setup of your E-mail Service Provider (ESP), it is important to understand that trust is a volatile construct as indicated in image one. Trust develops over time and needs constant care to stay at a high level. In this article, we are going to elaborate the importance of a warm-up plan to achieve a high trust level and how to build a plan that fits your needs.

The Warm-Up 

image two: the warm-up plan

The warm-up refers to an incremental process with the target to build up domain and IP address reputation leading to a high trust level with Internet-Service-Providers (ISPs). You can imagine the warm-up plan as a sports game with two teams competing with each other, as illustrated in image two. Your team's target is to score by getting into the trust zone. Each score will increase your domain and Internet Protocol (IP) reputation leading to a better game result. The key to win is not only to have the best players on the field, but also to have a plan that will allow them to succeed.

We have good and bad news for you. The bad news is that there is no industry standard around the warm-up. The ISPs are using different spam identification logic and hesitate to make their algorithms transparent. As a result, the warm-up process is not an exact science. Therefore, it relies on an iterative and experience-based approach. The good news is that we are happy to share our experience, best practice, templates, tools as well as our version of the iterative approach with you. With all of that, you will be equipped to define a plan that fits your business needs.

Before proceeding to the actual warm-up plan, please keep in mind that a warm-up plan does only work in combination with the deliverability best practices, as we have introduced in Welcome to E-mail Marketing. Just for you as a cheat sheet, let us reiterate the headlines for you:

  • Build trust with the right ESP setup, for example, enable your domain for DomainKeys Identified Mail (DKIM) based message authentication.
  • Use the right audience, for example, only engage with opted-in contacts.
  • Create relevant content, for example, use a consistent branding across all your e-mails.
  • Be relevant, for example, build your campaigns so they align to the needs and pain points of your contacts.

Sounds exhausting? We have to admit that doing it right will cost you some time. However, compared to the effort it takes to rebuild trust and fix a bad reputation, it is worth it. You will see the pay-off with every single e-mail campaign executed and your pay-off currency will be the recipient engagement that ultimately is building up a solid funnel for sales conversions.

Your Tailored Warm-Up Strategy

image three: warm-up plan overview

Step One: Assess the Need for a Warm-Up

When do I actually need to apply the warm-up? If one of the points below applies to you, you should consider to run warm-up activities:

  • You have a new dedicated IP or a dedicated IP-pool/range you want to send from.
  • You have a new shared IP (single/pool/range) you want to send from. Most ESPs will use pre-warmed IPs for this purpose that should eliminate or at least minimize the warm-up need. However, we recommend to still start with a minimal warm-up to double check the warm-level of the shared IP. It is a safety measure that takes minimal effort and will prevent a potential disaster, like getting assigned to a cold/half-warm shared IP and harm your domain reputation by using it.
  • You have a new domain or sub-domain you want to send from. Often enough, domains are not getting the needed attention, even though they are the most consistent entity of trust in e-mail marketing. IPs, content and alike come and go, but your domain does stay. It is important to remember that ISPs treat the domain reputation separately from the IP reputation.
  • You have not sent e-mails from a particular domain or IP for more than 30 days.
  • You have new contacts in your database resulting from one of the below activities:
    • You have acquired a net new contact list.
    • You have connected a new data source with new contacts and executed the initial data migration.
    • You have a high organic growth rate of your database. It is difficult to quantify 'high growth' in a generic fashion, but as a rule of thumb you can look at weekly growth rates of ten percent or higher.
  • You have not interacted with a significant portion of contacts within your database for the last six months or more and want to re-engage with them.

Looking at the variety of reasons for warm-up activities, you see why there is not the single plan that works for everyone at every occasion. Therefore, your first step should be to get clarity on the need for a warm-up. In the second step, you build a custom plan tailored to your needs. It is dangerous to follow a predefined plan and let it dictate every step of your execution.

Step Two: Select the Right Campaign

As we have learned already, the warm-up plan is an iterative process. This basically means that you will take one or multiple campaigns and throttle their execution to work with drips. If a drip is leading to the expected results, you will move on to the next one. This process continues until you reach a high domain and IP reputation level. As a result of the process, you need to take special care when selecting campaigns for your warm-up plan.

Your campaign should satisfy the below criteria:

Criteria Negative Example
The tactics of the campaign are proven and have resulted in high engagement rates in the past. Try to prevent net new or experimental tactics during the warm-up. To enrich your positive journey touchpoints, you want to run for the first time educational and product experience campaigns around some of your flagship products.
The audience of the campaign should be representative of your total contact base.

A 'thank you for your huge brand love' campaign is likely very targeted, therefore not representative for your total contact base and as a result does not fit the purpose.

The audience size of the campaign is representative of your biggest sized campaigns. An 'honored customer' campaign targeting one percent of your audience is not suitable.
The campaign execution timing and duration is not critical. A Black Friday campaign that needs to go out between 8-10 am is not suitable.
The campaign execution batch size should not be critical. A 'thank you for your order' trigger campaign with individual sends and not batch is not suitable.
The campaign execution can be throttled without a serious harm to your business. A 'flagship product announcement' campaign with an all-or-nothing message tactic does not fit the purpose.

Considering the above criteria, the following examples would be a good fit for the warm-up:

  • Newsletter: Probably one of the best candidates for the warm-up is the newsletter. Usually the newsletter is well established, leading to repeatable engagement rates, the targeting is minimal, the total recipient size is large, throttling the send does not harm and the execution timing is not critical.
  • Product launch: The product launch is in most industry a very good fit since it allows to work with a large audience that has many super engaged (previous buyers) contacts. If the product launch comes with a strict timeline, it might not be a good fit for you. The strict timeline will likely prevent the need for throttling over a multi-week period of time.
  • Welcome to our brand: A welcome e-mail is a good idea since it usually generates high engagement rates. However, it is often time critical and the total audience size is limited. Having said that, the best 'welcome to our brand' campaign should be created as series or a journey. If done so, you can often overcome the challenge of the audience size as well as time criticality.

Based on the above, you should be able to identify campaigns that fit the purpose of your warm-up. Next, you need to think about your audience selection. Generally, your campaign dictates the audience that should be selected, but you can do a lot to fine-tune the selection to serve best for your warm-up.

Step Three: Select the Right Segmentation Pattern

image four: segmentation pattern

Once you have selected your campaign, you will need to select the audience. As mentioned previously, the campaign defines the base segments that should be used. However, there is still the need for fine-tuning to best serve the purpose of your warm-up.

The goal of the fine-tuning is to identify the contacts within your audience that have the highest chance of engagement. Therefore, you should divide your base segment into buckets by number and recency of engagements (clicks and opens). There is no standard guideline that fits all. Nevertheless, the distribution shown in image four worked well in many of our engagements and we recommend it as a starting point for you to work with. You will also need to size your buckets according to your needs in the warm-up plan. Hence, you might need to change the recency or count parameter of your audience selection to fit the purpose.

If your base segment size is big enough, start to further break down the buckets by ISP. This will allow you to control your warm-up with a laser focus. Experience has shown that it makes sense to take special care of the dominant ISPs and combine the minor ones into mixed buckets.

Additional hint: If you are really completely new to e-mail marketing (new dedicated IP, new domain and new contact list), your first audience should comprise only of colleagues who will actively drive the engagement. Ask your colleagues to interact with the e-mail by:

  • open it
  • click on the call-to-action
  • move it into another folder
  • mark it as 'no spam' and 'important' where possible
  • add your sender address to the contacts/trust list
  • forward it to a friend or colleague who does the same
  • reply to it

Warm-Up Plan Definition

Now that you've learned the basics around e-mail warm-up plans, it is time to be concrete on how you can set up your own plan. The following factors need to be considered when creating your own plan:

  • Warm-Up Duration:
    The typical warm-up duration to get to a daily send volume of more than a million e-mails is 30 days. Depending on the e-mail volume you want to warm-up and the communication frequency, the time may be shorter or longer.
  • Ramp-Up Factor:
    The Ramp-Up Factor defines the increase of the sender volume from one day to another. While we recommend at the beginning a 1.2 ramp-up factor, you can increase the factor to around 1.6 once you have successfully conducted the first send outs. In any case, you should avoid ramp-up factors higher than 1.6. If from one day to another, you double the volume of e-mails you send, the ISPs might treat this as a suspicious sending behavior and your reputation will drop.
  • Start E-mail Volume:
    We have had good experiences with an initial e-mail volume of 50. If both your IP and domain are new, you might also consider sending the first messages to your colleagues. As described above, that will allow to test the setup in a productive environment and also drive the engagement.
  • Frequency:
    As we have learned already in this article series, it is crucial to have a regular sending pattern. This is especially important during the warm-up process. We suggest to have warm-up e-mails sent out every day. Weekly senders will need a significant more time to warm-up their IP/Domain. Considering that you need to be available to track and if necessary adapt your warm-up schedule, our example plan does not foresee send outs on the weekend.
  • ISP Distribution:
    As part of your preparation, you should analyze your customer base and the distribution of ISPs/Inbox providers. The e-mail distribution across ISPs needs to be incorporated into your warm-up plan as you want to have all ISPs warmed up. The following examples illustrates the need for that: During your warm-up process you are adding contacts from a country that you haven't targeted before. There are ISPs which are only available in certain countries, for example, in France. If you would from one day to another send a couple of hundreds or even thousands of e-mails to addresses - the messages might be blocked or placed into the spam folder.
    it is also important to understand that some ISPs (for example, Gmail or Microsoft) are more likely to need a longer warm-up period.

In general, there is not one warm-up plan that fits everyone. Based on the information above, you need to come up with your own plan. You are welcome to leverage the warm-up plan template we have created. By using it and adapting it to your specific context, it should work quite well.

Download the Warm-Up Plan Template

This warm-up plan template is referring to a dedicated IP address. Depending on your environment (for example, shared IP with a new domain), you will need to adapt the plan to your specific situation. The example can be seen as a conservative plan - with an already warm IP you might ramp-up faster.

Warm-Up Monitoring

To verify if your warm-up plan is successful, you need to analyze the e-mail metrics after every single campaign you execute. For your reference, you can find the relevant metrics and typical values in the introduction article Welcome to E-mail Marketing. For the warm-up, you specifically need to have a look at the following metrics:

Metric Significance and Meaning How to Analyze in SAP Marketing Cloud?
E-mail-Open-Rate If your e-mail-open-rate is below the industry average, it might be an indication that many of your messages are placed into the spam folder and thus your recipients cannot open it. It is natural that your first messages will make their way to the spam folder. Should this initial drop of open rates occur, we recommend to keep a close monitoring on this metric but first stay with your intended sending pattern. Typically, the open rates will improve over time. Use the Campaigns app, navigate to the campaign and look at the Performance tab.
Soft-Bounce-Rate A high number of soft bounces might be the result when ISPs are blocking your messages as you are sending too many. As there might be many reasons for a soft-bounce, you need to have a look at the Soft-Bounce Reason and Delivery Status Notification (see below). Use the Campaigns app, navigate to the campaign and look at the Performance tab.
Hard-Bounce-Rate Typically, hard-bounces are the result of invalid e-mail addresses. This should be avoided in any case. We have also seen hard-bounces as a result of sending too many messages. This would mean that you need to lower the warm-up speed. As for the soft-bounces, you definitely need to analyze the bounce reasons (see below). Use the Campaigns app, navigate to the campaign and look at the Performance tab.
Bounce Reason and Delivery Status Notification

To analyze why you have received bounces, it is very helpful to look at the following two pieces of information:

  • Bounce Reason: A status message of the ISP, why a message was blocked.
  • Delivery Status Notification (DSN Code): An industry standard is RFC 821, defining delivery status code. Every bounced e-mail will have the reason explained in the bounce code. Example: 550 Requested action not taken: mailbox unavailable

Option 1:

Use the standard delivered SAP Analytics Cloud stories for bounce reporting.

Option 2:

  • Use the Segmentation application and use the following attributes - depending on the ESP you are using:
  • Amazon SES: Attribute Interaction Reason. See the following blog for a detailed explanation: Amazon SES Error Code mapping
  • SAP Digital Interconnect: Attributes SOURCE_OBJECT_STATUS_CODE and CONTENT_DATA

In addition to the mentioned monitoring options above you can also use the Analytics and Report Gallery. The Campaign Success for Messages report shows how successful your email and text message campaigns are, for example, you can see how many emails are opened or how many clicks are done. You also get an overview about the data quality, for example, you see how many addresses are bounced or run in permission limits.

You can access the report by opening the Analytics and Report Gallery app. You will find the Campaign Success for Messages report as part of the Campaign Analytics content.

After selecting the report you have various filtering options, for example to filter for a specific time frame or by campaign or marketing area.

Your filters will be applied and you will be able to see the respective results. Afterwards you are able to use the drag & drop functionality to add dimensions. In addition you can also apply further filters or define specific conditions for your selected measures.

For example you could add the 'Campaign ID' & the 'Recipient Domain' into the rows and maintain a condition on your measures that will only include campaigns with bounces greater than X. With that you could easily identify domains that are causing bounces. In addition by adding the 'Business Document Status Code' as well as the 'Business Document Status Description' you could investigate on the bounce reasons and their descriptions.

Keep Your Reputation

We have explained how you can define your warm-up plan, by assessing the need for a warm-up, selecting the right campaign and the right segmentation pattern.

In addition, you learned about the significance of warm-up monitoring. But this should not be the last time that you monitor your campaigns and keep your sender reputation in mind. After getting your IP addresses warmed-up, it is very important to keep them warm. In order to do so, you should try to keep a predictable sending pattern, without major peaks or longer periods of inactivity. If you plan to send large number of emails on specific days, you should also look at your average send per day and steadily increase it prior to the high volume campaign. 

In addition to that, it is important to maintain a good list hygiene, keeping attention on soft- and hard-bounces, and doing pre-bounce checks. Please find more information on these aspects in the article 'E-mail Marketing - The Right Audience'.


In this article, you got to know how to do an important step in your journey of becoming an e-mail deliverability hero. By now, you should know the importance of trust and how to build it up with a solid warm-up plan.

However, we are not done here. Please make sure to deep dive into all aspects of your journey to become an e-mail deliverability hero:

In case you need further support, please refer to our dedicated 'E-mail Deliverability Guidance' service. You will find more details in the fact sheet that is linked in the services section of this article.