Campaign Studio

IP and domain warm up for email deliverability

The theory ‘work smarter, not harder’ applies directly to email delivery. Marketers spend much of their time planning, creating, testing, editing, re-working, and re-testing.

It does not matter how much time you spend or how great your marketing strategy is if your contacts never see the content. If you are smart in your approach to email delivery, your hard work as a marketer will pay off.


While Campaign Studio uses best of breed IPs to send your mail, we have no control over where recipients’ mail servers place your email. There is no technology that does. Campaign Studio offers you the tools and the knowledge to get great delivery, the practices and follow through is up to you.


Follow the best practices to support a great reputation and ensure that your emails have the best chance of delivery to your contacts.

  1. In your Campaign Factory Dashboard, complete the configurations for creating a Campaign Studio instance.

    Ensure that you have set up your custom domain, and configured and attached your sender domain.

  2. Set up a Preference center for your email recipients.

  3. Maintain a clean email list.

  4. Send a welcome message as soon as an inbound lead joins your database.

  5. Use Campaign Studio to watch for any trends of email fatigue.

    If a recipient has not opened any of the last four emails, dial back their frequency or change your content strategy for them.

  6. Follow the law.

    Whether CAN-SPAM, GDPR, or other regulations, the consequences of being outside the law are harsh. Email filtering/blocking is a common consequence of violating email rules.

Getting started

Reputation is everything when it comes to email delivery and directly determines if your email will be placed in the inbox or the spam folder. The following are two equally important reputations an ISP looks at when deciding where to place an email:

  • The reputation of the sending IP

  • The reputation of the sending domain

If you use Campaign Studio’s IPs to send through, Acquia ensures that all emails send through highly reputable IP addresses.

Next, we must warm up your company’s domain to establish a reputation with the Campaign Studio IPs.

Domain warm up

The Domain warm up process establishes the reputation of the domain with a new IP address. The warm up process involves sending emails from the new IP starting with small volumes and gradually increasing the volume on a set schedule.


During this process, send to highly active, engaged users who have opted-in and want to be receiving communication for the duration of the warm-up and beyond.

The more consistent the volume, frequency, and email stats (open, click, spam complaints, or other stats), the faster the domain establishes a positive sending reputation. If the sends are infrequent, anything less than weekly, the time to build a positive sender reputation increases.

Warm up schedule

Use this as a guide of the number of emails to send on a daily basis during the warmup process. Only send up to the maximum number of emails you plan on sending to your contacts on a given day.


Daily volume







































Pay close attention to consistent open rates, click rates, bounce rates, and spam complaints.


Source of this information is IP Warm-up Strategy Overview.

Engagement rates to strive for

  • Open: >20%

  • Click: >2%

  • Unsubscribe: <.2%

  • Bounce: <2%S

  • Spam: <.02%


If you notice significant changes in these rates, create a Support ticket.

Maintaining email reputation

Your reputation as a sender is crucial for the deliverability of your emails. Maintaining a strong email reputation is easier when your email follows these guidelines:

  1. Send emails that are relevant and correctly formatted

    • Wanted emails (clear opt-in during the sign-up process)

    • Relevant emails have content that is interesting and helpful to the reader

    • Correctly formatted HTML prevents filters flagging the email and users will complain

      • Review your email templates to ensure they are formatted well

      • Review sample content

        • Avoid:

          • All capital letters, special characters, and excessive punctuation.

          • Overusing terms such as exclusive, urgent, one-time only, free, cheap, pre-approved, $$$, and 100%

          • Red fonts or other colors that are non-accessible

          • Subject line:

            • Keep it short (<72 characters)

            • Offer value and create a sense of urgency

      • Review your email settings

        • Is the from header clearly you?

        • Is the reply-to configured correctly?

      • Use a testing service such as Mail Tester to learn how your email rates against various important metrics.

  2. List integrity is everything

    • How you build your list is critically important

      • Bad contact lists lead to increased bounce rates and spam complaints. These harm email reputation.

    • List hygiene: where you build your list and how well and often you update your list

      • If Contacts are not reading your emails after multiple sends or extended periods of time, it makes sense to remove them from your lists. One spam trap is a recycled spam trap. These consist of email addresses which were valid in the past, but were abandoned and picked up by mailbox providers to detect senders with poor email list hygiene who are not removing Contacts who are no longer engaged with their content.

      • A typo spam trap is also something to consider while cleaning your list. These are email addresses which contain spelling or other typographical errors and are indicative of poor address collection practices such as no double opt-in, sloppy data entry, or no address validation.


    You should not use Campaign Studio to purge your list for hard/soft bounces and inactivity. This damages email reputation and may result in suspension of your Campaign Studio instance.

  3. No wild swings in email volume

    • Regardless of the amount, ISPs like consistent volume each week or month.

    • Swings in volume hurts deliverability, and seems suspicious to the ISP. Planning email campaigns and cadences in a calendar help manage volume per week or month (for ISPs) and send frequency (for recipients.)

  1. Few spam complaints

    • If email recipients complain to ISPs or mark your email as junk or spam, ISPs can and will block your sender domain.

    • Keep the complaint rate below 0.1% of emails sent.

    • Evaluate your content (subject line, email body copy, images), your list, and your send frequency, and gauge the overall risk if even 1 in 1,000 recipients complains about your email.

  2. Avoid spam traps or honeypots

    • A pristine spam trap is an email address created by the ISP for the sole purpose of catching spammers. When a company sends to such an address, it tells the ISP that they’re engaging in illegal email address harvesting, or their practices for list hygiene are too weak.

    • Having even one of these on your email list causes instant and deep damage to your email reputation and deliverability.

  3. Low bounce rates

    • If your bounce rate is at 2.0% or greater, it notifies the ISP that your subscribers are not engaged or you have poor list hygiene. For tips to lower bounce rates, see Bounce Management FAQ.

  4. Zero blocked list appearances

    • Some ISPs block a sender domain if it appears on even one of the top blocked lists: Spamhaus, Barracuda, Invalument, and Spamcop

      Having a strong sending reputation is the only way to help convince administrators to remove your IPs from their list.

      Campaign Studio uses a best-of-breed ESP (SparkPost), which maintains the relationship with the ISPs. This also means if one of our customers is getting too many complaints, hard bounces or includes a spam trap address, then SparkPost makes it harder for that company to get their marketing emails delivered.

For more information on best practices for email delivery, contact your Customer Success Manager.

Reputation Recovery

A reputation can significantly and swiftly be ruined. If you notice a sudden decrease in engagement rates, or if your domain is blocklisted by ISPs, create a Support ticket.