Email Warm-Up


Email warm-up is the process of building trust for an email account with Internet service providers (ISPs). This process includes sending emails from a new email account, starting with a smaller number, and gradually increasing the number of emails each day.

As a marketer, you must establish a positive sender reputation for an email address before sending huge email campaigns. This helps to prevent your emails from being marked as spam and increase the likelihood of reaching your recipients’ inboxes.

Importance of Warm-Up

Email warm-up is essential when you want to send email campaigns with a new account to ensure emails land in inbox. With a warm-up, you can distinguish yourself from spammers and make your emails seem genuine to the ISP.

Unlike a traditional email campaign, email warm-up is specifically designed to improve deliverability. Even the best email marketing campaigns to highly engaged lists can still have low open and reply rates.

Reasons to warm up an email account before using it for outreach:

  • Establish trust as a valid email account, not a spam account
  • Increase deliverability
  • Build (or repair) your sender reputation
  • Scale your outreach faster 
  • Send campaigns to your full limits
  • Lower the chance of your account getting suspended for suspicious activity

ISPs are skeptics at best when it comes to deciding on emails' inbox placement. While authentication (DKIM and SPF setup) is important, it is not enough for the ISPs to trust you. You need to build the trust gradually by ensuring high engagement in your emails. If emails are coming from a new IP/domain that has not built a good reputation as yet, ISPs might handle your emails as follows:

  • Only accept a small number of emails
  • Receive emails at a slow pace
  • Place all emails in the spam folder
  • Send the first few emails in the inbox, monitor the engagement from the initial recipients, and then determine where to send the rest of the emails.
  • Block emails from you if you try to send more than a smaller number

Note: Your reputation with the ISPs can take a hit with even a single bad campaign. Recovering from such a setback can take anywhere between 4 to 8 weeks.

Guidelines for Warm-Up

As part of the warm-up, you need to send relevant emails to a small volume of users who are most likely to engage. The exact amount of time required to do this will depend on the current reputation of your domain/IP and the performance of your campaigns. The following are some high-level guidelines:

  •  Send lower volumes to begin with, increase them gradually, and throttle your campaigns. Do not worry about scaling up initially; instead, focus on generating positive engagement.
  • Send to users who are most likely to engage positively.
  • Pay attention to performance metrics, such as delivery rate, open rate, click rate, spam complaints, and unsubscribes. Course correct based on your observations.
  • Check your reputation on postmaster sites, and inbox placement data on third-party sites. Course correct based on your observations.
  • Monitor your performance metrics and reputation closely for the first ten days. After your reputation is stable, move to ramp-up.


Email Ramp-up is a deliverability best practice used to increase your daily email sending limit over time gradually. It involves sending emails to a small segment of your most engaged users and then gradually increasing the volume with each subsequent send.

Difference Between Warm-Up and Ramp-Up

Warm-up and ramp-up are not the same. The following are the differences:

  Warm-Up Ramp-Up
What is it? Is the process of building a positive reputation for any new domain/IP with the ISPs. Is the process gradually scaling up to the volumes you intend to send from a domain and/or IP.
When is it required? Is required whenever you want to start sending emails from a new IP and/or domain. Is required if your sending volume is going to be >50% of your average peak volume or if you have yet to send any emails in 3+ weeks.
Why is it required? Is required for you to ensure that your emails land in the inboxes of your customers. Is required for you to ensure timely delivery and inbox placement of your emails to your customers.
How fast is it? Is slow so it takes time to warm-up. Tends to be faster.

Importance of Ramp-Up

After building a good reputation, you need to increase the sending volume until you reach your daily average. The pace of ramp-up, however, should be determined based on the campaigns' performance and domain/IP reputation during warm-up.

  • If they are excellent, you can ramp up much faster and take some calculated risks.
  • If they are average, ramp up at a breathable pace, and progress cautiously.
  • If either of them is bad, fix it first.

Benefits of ramp-up:

  • Prevents sending too much too fast
  • Helps build a positive sender reputation
  • Avoids volume spikes that can trigger blocks
  • Simplifies warm-up pacing
  • Helps to safely scale your outreach

Guidelines for Ramp-Up

Increase your daily sending volume by 30%-50% each day. Ensure that your performance does not drop and that the domain and IP reputation stays consistent.

Your intended daily/weekly/monthly volume defines the volume you should ramp up to. For example:

User base Peak Volume Ramp up plan
100K 100K Ramp up to 100K.
100K 50K Ramp up to 50K.
100K General sending volume is 20K. Once a month, 100K. For general sending volume, 20K ramp-up will suffice.  For the monthly 100K send, you will need to use a segmented strategy.

Note: IPs start getting cold after 2 weeks, and thus higher infrequent volumes will require special handling.

You can control the volume during ramp-up in multiple ways:

  • Create smaller segments based on the daily prescribed volume.
  • Use control groups while creating campaigns.
  • If applicable, we will also enable back-end limits.


While ramp-ups are done at the time of onboarding, scale-ups address the seasonality in sales that most businesses observe. The marketing efforts, as a result, also need to follow the same cycles. In peak seasons, your sending volumes can be higher than usual. To meet the same, the emails sent need to be increased to those levels. This is known as a scale-up and is done in the weeks leading to the peak.

Typically, a larger user base at such times includes lesser engaged users, and hence an integral part of the scale-up becomes segmenting such inactive users based on their last activity/inactivity, sign-up date, sign-up source, and so on. This helps avoid any negative impact of the scale-up on your domain's/IP's reputation.



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