In this article, we’ll go into some detail about the importance of warming up an IP address before sending out emails. We’ll also cover best practices that for email distribution that will ensure your warm-up period goes well.

How to warm up an IP address before sending emails

Warming Up An IP Address

Are you ready to blast out emails with your own software? If so, then you’d better warm up your IP address first.

Why? Because if you don’t, various email providers might flag your IP as a source of spam.

When that happens, you can be sure that you’ll limit your reach. In fact, your whole email marketing effort will likely fall apart.

Warming Up An IP Address – Email Service Providers Are Watching

When you’re getting started with a new email marketing initiative, you might choose to use your own software for distribution. Obviously, that software will run on an SMTP server connected to the Internet and have its own IP address.

Once the software starts sending out emails, email service providers will check them to examine the point of origin. They do that so that they can reduce the risk of spam getting through to their users.

If an email service provider finds an unusually high number of emails coming from the same IP address in a short period of time, that provider will almost certainly flag the IP address as a spammer. Then, the provider will put emails received from that source into the dreaded “spam” folder.

That means recipients will probably never see the email. After all, not too many people actively check their spam folder for marketing messages they might have missed.

In other words, if you don’t warm up your IP address, you’re going to dramatically reduce the number of people who see your emails.

Since that’s the exact opposite of what you’re trying to accomplish with email marketing, you need to warm up the IP.

What Does It Mean to “Warm up” an IP Address?

So what, exactly, does it mean to “warm up” an IP address? In a nutshell, it means to send out emails slowly at first and then blast out emails later on.

When you follow that approach, email service providers have a chance to note that you’re not spamming right out of the gate. They’ll also pay attention to how recipients respond to your emails.

If service providers find that recipients are opening your emails, clicking links in them, and responding to them, then you’ll get on the white list after a while.

Basically, you need to establish your reputation before you can start sending out email in heavy volumes.

There Are Some Caveats, Though in Warming Up An IP Address

When you start the warm-up process, you still need to follow email marketing best-practices or your IP will get flagged as a source of spam anyway. That’s true even if you’re only sending a few emails.

Specifically, follow these guidelines:

  • Comply With the CAN-SPAM Act – The CAN-SPAM Act, passed in 2003, establishes legal standards for sending commercial email. If you fail to comply with any of the basic provisions in the law, you might get fined thousands of dollars in addition to ending up on a blacklist. Here are the 7 basic provisions:
    • Don’t use false or misleading headers
    • Don’t use deceptive subjects
    • Identify the email as an advertisement
    • Tell recipients where you’re located
    • Tell recipients how they can unsubscribe from your list
    • Honor unsubscribe requests promptly
    • Keep track of what others are doing on your behalf
The CAN-SPAM act establishes legal standards for sending commercial email

The CAN-SPAM act establishes legal standards for sending commercial email

  • Avoid Phishy Phrases – Phishy phrases are phrases in the subject or body of the message that make it look like you’re phishing for a password or personally identifiable information (PII). If your emails contain any phrases like “click this link to reset your password” or “we need to confirm your billing information” then you might get flagged.
  • Include a Text Version of Your Email – If you’re accustomed to sending out HTML-only versions of your email, break that habit now. Make sure that you send out a text-only version as well.
  • Send Only to People Who’ve Opted In – Your email distribution list should be filled only with the email addresses of people who’ve specifically requested to receive emails. Trim your list of anybody who didn’t sign up to your distribution list.
  • Use Spam Checkers First – There are countless spam checkers available for use, including SpamAssassin and IsNotSpam. Pick the tool that you like best and run your email through it. Follow any actionable insights you receive from the report.
  • Have a Good Text-to-Image Ratio – If you must use images in your emails, make sure that you also use plenty of text. An image-only email is a sure sign of spam.
  • Avoid Attachments – The last thing you want to do is clutter up someone’s email space with a an attachment. If there is a file that you want people to download, just put a link to it in the body of the email itself.

When You Don’t Need to Warm up Your IP Address

In some cases, you might not even need to warm up your IP address.

If you’re using a well-known autoresponder such as AWeber, MailChimp, or GetResponse, you’ll likely find that those services already use IP addresses that are well-known to countless email providers. You probably don’t need to worry about any warm-up procedures in that case.

However, it’s still a good idea to get in contact with your rep at the company and ask if it’s necessary to warm up the IP.

How to Warm up Your IP Address

There are 2 ways to warm up your IP address. We’ll cover each of them in detail here.

First, you can manually warm up the IP. That’s a simple process that involves starting out with just a few emails and sending out more and more over time. When you do that, you should use the following warm-up schedule:

  • Day 1 – 50 emails
  • Day 2 – 100 emails
  • Day 3 – 500 emails
  • Day 4 – 1,000 emails
  • Day 5 – 5,000 emails
  • Day 6 – 10,000 emails
  • Day 7 – 20,000 emails
  • Day 8 – 40,000 emails
  • Day 9 – 70,000 emails
  • Day 10 – 100,000 emails

If you need to go higher than that, you’ll see a great schedule here that you can follow. There’s another chart at that link that also shows you how many IP addresses you should have based on your daily email volume.

Manually warm up the IP by following a schedule

Manually warm up the IP by following a schedule

The other option for warming up your IP address is to use a service that warms up the address for you. SendGrid is one such service.

With SendGrid, you can set up an automated warm-up with the user interface. Alternatively, you can use the API to automate the warm-up process.

You’ll probably need to enlist the aid of a developer if you want to use the API.

Wrapping It Up Warming Up An IP Address

If you’re serious about email marketing and using your own software to send out emails, it’s very important to warm up your IP address. Otherwise, you’re likely to get branded as a spammer.

Fortunately, it’s not that difficult to warm up an IP address. It just takes a couple of weeks and a little effort for most marketers.