How to Improve Email Deliverability with Apollo

Article author
Xier Dang

Abstract graphic with a person cruising through the sky towards the right destination


It doesn't matter how much of a wizard with words you are, or how good your email strategy is, if your emails aren't landing in your prospects' inboxes. Before you embark on any email outreach, you must follow deliverability best practices and set your mailboxes up for success.

Check out the following sections to maintain a healthy domain reputation and improve email deliverability rates with Apollo.

Email Deliverability by the Book!

Want to uncover make-or-break email deliverability tips, tricks, and best practices? Hop into Chapter 7 of our shiny new book, Outbound Sales, to learn:

  • How to avoid the spam folder.
  • How modern spam filtering has changed.
  • How to unlearn common deliverability myths.
  • How to properly set up your cold email sending infrastructure.
  • Ensure you're sending wanted emails.

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How to Track Email Deliverability in Apollo: A Checklist

Email deliverability is a tough nut to crack and not easy to understand. For most, it’s a black box. For everyone, it's an ongoing process that's never a one-and-done exercise.

Use Apollo to visualize areas of opportunity and gain actionable insights to improve your deliverability rates.

A Splash of Deliverability Wisdom

Apollo recommends that you opt for quality over quantity. You should write and send emails like a real person. Your recipients receive multiple outreach emails every day and it only takes a moment for them to click "spam".
So ensure you research well and leverage Apollo's data and personalization features to tailor your messaging to each prospect. The more clearly you define your ideal customer profiles and segment your lists when prospecting, the more relevant your messages will be.

Follow this 8-step deliverability checklist to make ensure your emails land in the right inboxes at the right time.

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Step 1: Configure and Authenticate Your Domains

You may need your IT, engineering, or web team to complete these steps.

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Step 2: Set Up Your Mailboxes and Configure the Settings

Once you've linked your mailboxes to Apollo, make sure you:

  • 50 emails per day. You can increase this if you have a healthy domain reputation and your outreach sequences consistently gain more than a 5% reply rate.
  • 6 emails per hour
  • 600 second delay between emails

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Step 3. Warmup your emails

If you’ve just set up a new email domain, we recommend that you manually warm it up before using it for any email campaigns by following general best-practices below.

  • uncheckedDon't start sending until a domain/subdomain has been around for at least 30 days.
  • uncheckedRun each new connected mailbox through the inbox ramp-up warmup. 
    • Inbox ramp-up is an email warmup solution that gradually and automatically increases the number of emails sent per day over the course of two weeks. It’s a warmup approach that adheres to best practices from email providers like Google and Microsoft, ensuring a smooth increase in your sending activity. 
    • Run inbox ramp-up warmup for every mailbox you connect to Apollo.
  • uncheckedAsk your closest contacts to respond to your emails first. If possible, then forward them as well. (Mailbox providers track opens and clicks which helps to signal that you’re sending relevant or “wanted emails.”)

Step 4. Use good targeting and clean data


Step 5. Monitor your domain sender health


Step 6. Structure your email content

  • uncheckedFormat your messages like a real person would when sending to a peer. Avoid excess design elements in your email, like:
    • Promotional images. You can use images but not in a way that feels spammy.
    • HTML tables and other formatting
    • Don’t go crazy with bold and italics
  • uncheckedInclude few (if any) links
    • If you must include links, always use secured (https://) and not (http://)
    • Show the full link, instead of linking the URL to CTA text like "Click Here".
    • Don't use public link shorteners like or link to files in Google Drive. That looks suspicious!
  • uncheckedDon’t include attachments 
  • uncheckedYou included an opt-out link or set up one-click unsubscribe, right? 


Step 7. Advanced tactics

  • uncheckedLeverage subdomains and non-primary domains to limit the impact of deliverability disruptions and to "fence" off different types of emails (sales, marketing, transactional)
  • uncheckedLeverage multiple inboxes (ideally across multiple subdomains / domains ) by linking additional mailboxes to Apollo and using mailbox rotation — as long as you're acting like a legitimate business sender
    • Be sure to set up SPF, DKIM, and DMARC records for these, too!
    • Before you add multiple domains make sure you’re sending enough with the first domain. It’s better to send emails using subdomains and accounts before using fresh domains. 
  • uncheckedSet up multiple A/B tests for each email in a sequence — this allows you to experiment with subject lines or email content to optimize for high-engagement emails 


Step 8. Repair damaged deliverability

  • uncheckedStop using the damaged domain and warm until health is restored (weeks to months)
  • uncheckedRotate in a ready domain (should be properly aged and warmed)
    • uncheckedIf you don't have one, set up and warm additional subdomains / domains
  • uncheckedUse alternate methods of outreach during recovery, including calling and LinkedIn
  • uncheckedReconfigure your setup to look like a legitimate business sender (by following the steps above) and continually monitor your domain reputation
  • uncheckedScale up slowly (~25 additional sends per day), starting with your most receptive audiences (e.g., personal contacts, only engaged prospects —using engagement activity filters)


For professional help with your deliverability for outbound, contact Apollo partner Senders.
Have support questions? Reach out to Apollo technical support.