Answers to Your Burning IP Warm Up Questions


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We had a great turnout for our webcast ISPs Like It Hot: How to Warm Up an IP this past Tuesday! Our Senior Technical Account Managers, Katie and Aku led us through the benefits of IP warm up and the ugly consequences of not taking the time to do it. To start things off, check out our quick Webcast Byte that explains who needs to warm up their IP:

We had a TON of questions and couldn’t quite get to them all- so here are the answers to a hand-picked bunch that we felt covered a variety of topics.

Is there a tool or service to check the “temperature” of a new IP?

Yes, SenderScore.org is a free service that allows you to check the health of your IP.

My account is associated with a dedicated IP. It is warmed up. If I add a second IP to the same account will SendGrid balance sending volumes taking the new IP into consideration, or do I have to use separated subusers?

You will still need to take the time to warm up this new IP. This can be done by setting up a subuser account and sending a portion of your mail through this subuser account until the new IP is warm. Once the new IP is warm, you can simply add it to your primary sending account and SendGrid will balance the load evenly between those two IPs.

Can you whitelabel even if you don’t have a dedicated IP?

No, you must have a dedicated IP in order to whitelabel. At SendGrid, you receive a dedicated IP once you upgrade to our Silver plan.

How do you clean up your email database that may be up to 2 years old?

Check out our blog post on list hygiene.

If I send a million emails every month, and don’t have a dedicated IP, how will ISPs (like Google) treat me differently?

ISPs will react to how all users who are receiving mail from your shared IP are acting. This could harm you if another user on your shared IPs are sending unwanted mail to their users. If the ISPs see that users are not engaging with a portion of mail or that “spammy” mail is coming off of those IPs, they could send a portion (or all) of the mail from those IPs to the spam folder. When you’re sending at this volume, it’s highly recommended that you have a dedicated IP so that only you are responsible for your IP’s sending reputation.

What volume do you recommend starting sending with on Day 1?

We typically recommend you send about 2,000 emails on day one. Specifically that volume split up across the major ISPs (Yahoo, Gmail, Hotmail, AOL, etc.).

Is it recommended to warm up a dedicated IP for marketing with transactional email?

Yes. If possible, it’s best to start a warm up with transactional email as this type of mail typically has higher user engagement. Once you warm up the IPs with the transactional mail, you can simply move a couple of those warmed IPs over to a subuser where you’ll send your marketing emails from.

After an IP is warmed, will inconsistent sending affect your deliverability rates?

Yes it will. It’s always best to establish a regular sending cadence both for the ISPs and your recipients. This allows you to set expectations with both parties (ISPs and recipients) that your brand sends emails on these days.

If I don’t send any emails on one day, should I start warming up from beginning or where I stopped? Example: sending emails on all days of the week except Sunday.

Not if this is your typical sending cadence. Once your IP is warmed, you do not need to send every day. If you stop sending for 4 weeks, you’ll want to re-warm up the IP.

Do you have any recommedations on how to warm up an IP for a seasonal event (i.e. Olympics, Super Bowl) where sending off-season content isn’t really relevant? 

If possible, start sending event announcements or related content to your users a week or two prior to the event. This will help hype your recipients up for the big day and the great content that is to come. If you take more than a month off between your sends, you’ll want to go through this process of warming up the IP each time you’re getting ready for a big event. Also, depending on the volume, you may be able to ramp up very quickly.

If you weren’t able to attend the webcast, view it in its entirety for free on-demand here. Of course, if you have any questions that were not answered in this post, feel free to download our comprehensive guide on the topic, How to Warm Up an IPor reach out to our kickass support team!


When Kate isn't trying to teach herself the ukelele, make it through the mountain of books on her nightstand, or figure out if they are actually being serious about suggested serving sizes on ice cream, she is the Content Marketing Coordinator.

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