Email Domain Warming

What can you do to build your domain reputation and avoid your emails landing in junk?

Georgina Doyle avatar
Written by Georgina Doyle
Updated over a week ago

We use a selection of pool IP addresses at Airship to ensure you always get the best possible deliverability from your emails, you can see the list of IPs to whitelist here, this also means you don’t need to warm your IP address as a new Airship customer. However, if you choose to create your own branded subdomain (instead of the Airship house domain) you may need to warm up your domain before you send any emails to a large audience.

Why do you need to warm your domain?

The purpose of domain warming is to improve your domain reputation and gain ESPs' trust so all your emails can be delivered right into recipients' inboxes (and not be blocked by spam filters). Before we lay out your domain warming plan let’s look at what impacts your domain reputation in general.

What impacts your domain reputation?

When you create your branded subdomain (guide on how to do this here) we automatically implement all of the authentication needed to send your emails successfully but other things can impact your domain reputation which you need to be cautious of, particularly when you're sending from a new domain.

  • Email deletion - the number of contacts that deleted your email

  • Spam reports - the number of spam complaints that your domain receives.

  • Unsubscribe requests - people who unsubscribe from your emails.

  • Email content - the quality of your messages, usage of spam words, grammar mistakes, the trustworthiness of links (if included), etc.

  • Engagement rate - the number of people who opened, replied to, or forwarded your emails.

  • Blacklists - The reputation of a domain address can suffer if it is put on one of the popular email blacklists.

  • Bounce rate - the number of emails that were not delivered to recipients' inboxes.

So what can you do to build your reputation?

As Well as creating & warming your branded subdomain there is also much more you can do to build up a positive reputation and ensure your email delivery is as good as possible.

Avoid spam words in your emails

ESPs can detect words that are often used in “spam” emails, to avoid being marked as spam and your lovingly crafted emails landing in your guests junk boxes make sure you’re avoiding any of these commonly used words.

We don’t have a definitive list of the spam triggers but try to avoid words such as “FREE” “20% OFF” “LIMITED TIME ONLY” “BUY RIGHT NOW” etc, including words in capital letters can also be a trigger.

Make sure your email content is relevant to your guests and to a high quality.

Personalise the message. Make use of Airship’s merged content to include guests names and favourite location within the body of your email.

Keep an eye on the length of your email. Longer emails can get clipped when they’re sent by certain ESPs which can flag as an issue when the email is sent, be conscious of how long your email is and try to keep the content short and concise.

Keep an eye on how often you’re sending to the same guests. We really encourage you to send regular emails via your Airship account but these should be segmented where possible, think about why you’re sending that content to those people and whether the content is relevant to them.

Split test your subject lines. Airship gives you the option to split test your subject lines, this helps to see which subject lines work for your guests and it also breaks down the size of the send which will help to enhance your delivery.

Clean your email lists

Implement a retention email. Retention emails are a great way to keep your database clean, they are triggered to guests after a certain amount of inactivity (we recommend triggering these when a guest hasn’t read an email for 6 months) if the guest reads this email they will remain on the database but if they don’t they will be cleaned and removed. You can include a really strong offer in here to entice them back in!

Exclude your unengaged guests. We automatically do this for you at Airship! This means that if a guest hasn’t read one of your emails for 6 months or more they are excluded from your email sends, you can overwrite this but we wouldn’t recommend you do this more than once a month.

How should you warm your IP?

We recommend splitting your first sends through your new domain down into smaller batches as well as split testing these to trickle the sends out even further.

We’d recommend sticking to the below schedule until you’ve sent to your entire database:

Day 1: 50,000

Day 2: 100,000

Day 3: 200,000

Day 4: 400,000

Day 5: 800,000

And continue to double your send each day until you’ve sent to your entire database.

Having automated emails going out ahead of your campaign emails will really help to contribute to this warming as the emails will be sent to a smaller number of guests each day.

Get in touch with our team on if you have any other questions.

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