What is IP Warming?

You just got yourself a shiny new IP address and you’re ready to blast out 100,000 emails in your first day!  There is one problem…you can’t do that. Well, technically you can, but you definitely don’t want to. If you haven’t gotten the memo yet, there’s this thing called a sender reputation that mailbox providers like Gmail, take VERY seriously.  The worse your reputation is, the less likely your emails are to make it to the inbox. So when you blast out 100,000 emails on your first day, your sender reputation goes down and your deliverability goes down with it. How do you fix this problem and maximize your deliverability? Through something called IP warming.

IP warming is the process of warming up a new IP address by gradually increasing the volume of emails sent from it over a period of time.  In many ways IP warming is similar to an athlete warming up, or a cold engine warming up, or you warming up to your new mother-in-law. Maybe not the last one but you get the point. Sometimes you have to let things warm up to make sure they don’t break…in this case, an IP address.

Why Warm up a New IP Address?

IP warming is just one of many pieces in the puzzle that is email deliverability, and it’s one of the single most important pieces to consider.  Given the right circumstances, IP warming, or the lack thereof, can be the single biggest contributing factor to your poor email deliverability.

Mailbox providers like Gmail pay very close attention to where mail is coming from, where it is going, how much is going, and what that mail looks like.  If they have any reason to believe that spam or phishing related emails are being sent from an IP address, they will take swift action to decrease the sender’s ability to deliver email .  One of the biggest triggers is email volume. If a new IP address with no existing reputation starts sending out bulk email in a short period of time, they will mark it as spam, no matter how legitimate the mail is.  Once your sender reputation goes down, your deliverability goes down, your engagement goes down and you lose business. IP warming is the best way to avoid this slippery slope and build up a positive reputation, but it’s not as simple as it seems at face value.

How to Warm up an IP Address?

It’s important to note that there is no single tried and true way to warm up every unique IP address.  Each user will have diverse needs and goals that might make their IP warming strategy different from the next. For example, a sender switching to a new email service provider (ESP) from an old one, compared to someone starting with an ESP for the first time, will have different needs. Not only is everyone’s situation different, but more importantly their send volume will vary too, are you sending 10,000 emails per month or 800,000?  All of these factors, and more, need to be taken into consideration before creating an IP warming strategy. A good ESP will create and deliver this strategy for you.

IP Warming Strategy for New Senders

So it’s your first time working with an email service provider and you may not know all of the rules and regulations that go in to delivering your marketing and transactional emails. A good ESP will have years of experience in email best practices like IP warming that will help you achieve maximum deliverability.

A rather conservative and very general method used to warm an IP address for new senders is to equally distribute your sending across all mailbox providers, and by each day of the month.  For example, if you’re sending 100,000 emails in a month, an ESP might divide those 100,000 emails to send equally on each day of the month to each mailbox provider. So each day you might send 1,111 to your Gmail addresses, 1,111 to Yahoo! addresses, and 1,111 to Verizon addresses until you hit 100,000 messages that month. This safe and calculated approach will help your IP address stay under the radar to big mailbox provider spam traps and content filters and help drive your deliverability.

If this method proves to be working well and your deliverability/engagement rates are healthy, then it’s time to consider increasing the amount of email sent over the given time period.  A good ESP will have a comprehensive dashboard of all important rates and metrics that will allow you to see, first-hand, trends in your email deliverability. From these metrics, an ESP can help determine the warming “sweet-spot” for your unique IP to achieve maximum deliverability.  Again, there is no definitive delivery rate that applies to all IP addresses; planning a warming schedule is done on a case-by-case basis, typically by an email service provider.

IP Warming Strategy for Switching Email Service Providers

It’s a pretty common occurrence that a customer signs up with an ESP and realizes that they just aren’t getting the support, analytics and deliverability they wanted.  Rightfully so, they make the switch to a new ESP like SocketLabs. To properly warm up the new IP address with SocketLabs, it is a good idea to gradually transition email sending from your old service provider to your new one.

For example, if you send 200,000 emails per month, maybe you want to switch 100,000 email to your new ESP for the first month to let that IP warm up.   Following this strategy, you avoid the risk of blasting too many emails, too fast, through your new provider. If you want to make the switch immediately, you can follow the same strategy that a new sender would.  Regardless of your unique situation, working with a good ESP will ensure that you adhere to IP warming best practices.

How to Optimize IP Warming?

While a good ESP can cover all of the IP warming for you, there are some areas that you, a sender, can focus on to improve your deliverability as well.  No matter what your situation is, while warming your IP address, it’s very important that you are putting your best foot forward. This means that you want to follow three important email sending best practices:

  1. Sending your high-quality, high-engagement campaigns that have done well in the past
  2. Cleaning off addresses that bounce or complain
  3. Monitoring your engagement/overall performance metrics very closely

You should also consider that ISPs place a huge weight on email authentication. If you do not have proper SPF, DKIM, and DMARC authentication securing your email,  then you might see a significant decline in your deliverability.  Email authentication is an entire topic in itself. 

All Things Considered

By nature, IP warming is a fairly simple concept to grasp, especially when compared to other, more technical, email topics.  While the concept itself is simple, there is a lot that goes in to it as a sender. Missing the mark just slightly and sending too many emails from an IP can destroy your sender reputation.  That’s why good email service providers, who have years of experience, can take your unique situation and follow all of the necessary steps to make sure your new IP is healthy and achieving maximum deliverability.