Email Marketing Services
Warm Up period


What is it? How to go through it?


Every time that a new email marketing project with dedicated IP addresses starts, the same concept comes up as a base to begin to build a good relationship between the sender and the different ISPs: the warm up period. It is repeatedly referenced but what exactly is it?

When a new group of IP addresses (or just one) has no records of deliverability over it, there is not such a “reputation” that can tell to the ISPs whether they should trust or not in the sender who is using these addresses. Thus, we can say that the warm up period is the time that takes to reach certain level of confidence on the ISPs side from which the reputation score is set as good.

As you might picture, this period is a must: you cannot avoid it. Nevertheless, you can make it painless and not longer than necessary just by following a few good practices that, moreover, will have a good impact to the success of your email marketing program:

  • Check the reputation of the IP addresses before going ahead. Sites like senderscore.org or senderbase.org will give you a big picture about them. If they don’t show volume in the last weeks and so that they have neutral or inexistent scores, you’re in the good path. If they show volume and/or a bad reputation score, try to change them to others which not. If you’re using an Email Service Provider, talk to them. They know what you’re talking about.
  • Use a new, separate domain exclusively for the communication you’re about to start. Domain reputation is becoming more and more important and if you are using a domain with bad reputation it will impact very negatively to the warm up period.
  • Report the beginning of the activity to the most important ISPs. Usually top ISPs will fill your subscriber’s database. They have tools to inform them that you are going to send emails from new IP addresses. Use these tools: Hotmail, Yahoo! or AOL count on them. Let them know what you intent to do is a good practice. This way not everything will be new for them.
  • Avoid volume fluctuations. Send all emails at once since the beginning or increase gradually the number of emails during the time until you reach your entire database (my favorite) but don’t create peaks of volume. This is a well-known spammer practice and ISPs don’t like it.
  • Send emails to double opt – in addresses, so you can avoid hardbounces and complaints that will turn the warm up period into something more difficult to get through to.
  • Deal with bounces and complaints meticulously. For sure exclude hardbounces but also certain softbounces like long period full inbox messages accounts. Configure feedback loops for all ISPs you are going to send when available.

Maybe a last one advice would be to apply common sense. You work in email marketing. You know what’s wrong and what’s a good practice. Avoid wrong ones especially in this period!