Last week I wrote about domain authentication, the technical setting that tells Gmail and Outlook your emails are safe to deliver. If you haven’t checked yours yet, that’s the place to start. You can read it here: Flodesk Domain Authentication Explained.
This week is the natural next step. Even with authentication done correctly, a new or recently changed sending domain still needs one more thing before it’s fully trusted by email providers. That thing is called domain warming, and it takes time, which is exactly why it belongs on your list now, not in October.
What is domain warming?
Email providers like Gmail and Outlook don’t just check whether your domain is authenticated. They also watch its history. A brand new domain that suddenly sends thousands of emails on day one looks suspicious, no matter how good the content is. A domain that starts small, earns good engagement, and grows its sending volume gradually looks trustworthy.
That gradual buildup is domain warming. It’s less a technical setting and more a pattern you create over several weeks, one that shows providers your emails are wanted, not spam.
Who needs to warm a domain
This applies to you if any of the following are true:
- You’re new to Flodesk and setting up your custom domain for the first time.
- You recently switched to Flodesk from another email platform.
- You changed your sending domain for any reason, even if you’ve used Flodesk for a while.
- You haven’t emailed your list in three months or more.
- A long period of silence resets some of that trust, even on an established domain, and a sudden spike in sending after going quiet looks the same to email providers as a brand new domain sending too much too fast.
If none of these apply and you’ve been sending consistently from the same authenticated domain, you likely don’t need to warm anything. This step is for new, recently changed, or recently reactivated setups.
How to warm your domain in practice
The same gradual approach applies whether your domain is brand new or simply went quiet for a while. Either way, providers are watching for the same signal: consistent, wanted engagement building up over time, not a sudden jump in volume.
Start with your most engaged subscribers first. These are the people who open and click consistently, not your full list. Sending to them first signals good engagement right away, which is exactly what providers are watching for.
Increase your send volume gradually over several weeks rather than emailing your entire list at once. There’s no single official number here, but a common approach is to start with a small, engaged segment and expand a bit more each week as your opens and clicks hold steady.
Watch your analytics closely during this period. If you notice open rates dropping or spam complaints increasing as you expand, that’s a sign to slow down rather than push through.
Keep your content genuinely valuable during this stretch. Engagement is the signal you’re trying to build, so this isn’t the moment for a purely promotional send.
Why the timing matters right now
This is the part that makes summer the right moment to do this, not a coincidence. Domain warming isn’t something you can compress into a few days. It takes real weeks of gradual, consistent sending to build a reputation that holds up.
If you wait until October or November to address this, you’ll be trying to warm a domain and run your biggest campaigns of the year at the same time. That’s a hard position to be in, and it’s the kind of thing that turns Black Friday into a scramble instead of a plan. Doing this work now, while things are quieter, means your domain is already trusted by the time your list traffic ramps up for the holidays.
If you skipped this step
If you’re realizing now that you set up a new domain or switched platforms and never warmed it properly, it’s not too late. It takes patience, but a domain reputation can be rebuilt with the same gradual approach. The sooner you start, the more settled things will be before Q4.
Not sure where your domain stands?
Between authentication and warming, there are a few moving pieces, and it’s easy to get partway through without realizing something’s missing. If you want someone to look at your setup and tell you exactly where things stand, that’s something I can help with directly, either in a 1:1 consultation session or as part of a Migration and Setup project.
A consultation session is the right fit if you want to go through your settings together and understand what’s happening. A setup project is the right fit if you’d rather hand it off and have it done correctly from the start.
If you want your domain fully settled before your list gets busy in October and November, this is the moment to check it, not after your first campaign underperforms.
This is post two in Your Summer Email Tune Up. If you missed the first one, start with domain authentication, since warming builds on that foundation.
