Keeping Your Outreach Emails Out of Spam

An email that lands in the spam folder instead of the inbox is essentially a wasted effort. Let’s go over the reasons why emails get flagged as spam and explore solutions to ensure your hard work isn’t lost in cyberspace.

1. The Basics: Domain & Email Addresses

What Is a Domain?

A domain is the web address people type into their browser to find your website (e.g., yourcompany.com). When you create email addresses like name@yourcompany.com, you’re using that same domain to send and receive emails.

What Is a Subdomain?

A subdomain is an extension of your main domain (e.g., outreach.yourcompany.com), often used for distinct purposes like email campaigns or separate lines of business.

Why Not Use Your Main Website Domain for Outreach?

• Risk of Domain Reputation Damage: Sending large volumes of outreach emails from your main domain can invite spam flags or complaints. If Email Service Providers (ESPs) detect “spammy” patterns, they can lower your domain’s overall reputation—even affecting legitimate daily correspondence.

• Risk of Blacklisting: If your primary domain gets blacklisted, you’ll need time-consuming remediation to restore it. Meanwhile, regular business communications may also suffer.

Suggestion: Use secondary domains (like yourcompany.io) or subdomains (like outreach.yourcompany.com) for cold outreach. If something goes wrong, your main domain remains protected.

2. How Email Providers Evaluate Your Emails

Most Email Service Providers—whether consumer-focused like Gmail and Outlook, or business-focused like Google Workspace and Microsoft 365—grade incoming emails on several factors:

1. Sender Reputation – Tied to your domain and IP address.
2. Subject Line & Email Content – Keywords, formatting, and overall message quality.
3. Sending Patterns – Frequency, volume, and email scheduling.
4. Engagement Rates – Opens, clicks, and replies. A combined engagement rate of 20% or above is preferred for a successful campaign.
5. Hard Bounce Rates – The percentage of emails that failed to deliver because the email addresses do not exist or are invalid.

• Healthy Bounce Rate: 0% – 2%
• Moderate Bounce Rate: 2% – 5%
• High Bounce Rate: 5% and above

6. Spam Complaints – If too many users mark your emails as spam, your reputation plummets. Keep spam complaints at 1% or lower to maintain deliverability and avoid blacklisting.
7. Including Too Many Links – Emails with excessive links can appear spammy and may be flagged by email service providers. This risk is higher if the links point to domains that don’t align with the sending email address or lead to external sites that are not well-established or trusted. To optimize deliverability, limit your email to two or fewer links, ensuring they are relevant, trustworthy, and closely aligned with your domain.

These providers use advanced algorithms to protect their users from unwanted mail. They have some of the most talented engineers with immense resources dedicated to filtering spam. Understanding how they judge emails is the key to staying in the inbox.

3. Is Your Domain New? Understanding Domain Reputation

Domain Reputation

Each domain builds a reputation over time based on how many emails it sends, how recipients interact with those emails, and how often it hits spam traps or blacklists.

Domain Blacklists

Various third-party organizations maintain blacklists of domains suspected of sending spam. Some well-known blacklist checkers include:

• MxToolbox

• Spam Eating Monkey

• Spamhaus

• Barracuda Central

When you register a brand-new domain, some blacklists automatically flag it temporarily. That’s why you might discover your fresh domain has a low or neutral reputation initially. You may need to wait until it’s automatically removed from those lists and then “warm it up” to prove it’s trustworthy.

Suggestion: Periodically check your sending domains on blacklist sites—especially if you notice a dip in open or reply rates. MxToolbox or similar tools can help you keep tabs on your domain’s status.

4. Technical Setup: The Critical Role of DNS Records (TXT, CNAME, SPF, DMARC, DKIM)

What Is DNS?

Domain Name System (DNS) translates domain names (like yourcompany.com) into IP addresses. Properly configuring DNS records is crucial to authenticate your emails.

To prevent spoofing and prove you’re an authenticated sender, configure these DNS records:

• SPF (Sender Policy Framework)
  A TXT record specifying which IP addresses and domains can send emails on behalf of your domain. This confirms your emails are genuinely from you.

• DKIM (DomainKeys Identified Mail)
  Adds a cryptographic signature to your emails, verifying they haven’t been tampered with. The signature helps validate your email identity.

• DMARC (Domain-based Message Authentication, Reporting & Conformance)
  Instructs receiving servers what to do (reject, quarantine, or do nothing) when an email fails SPF or DKIM checks. It helps identify messages attempting to impersonate you.

• CNAME & Additional TXT
  Sometimes required by email-sending platforms for link tracking or other verifications (like verifying ownership of your domain).

Suggestion: If technical setup isn’t your specialty, consult your domain registrar’s or email platform’s documentation—or consider hiring a professional. Improper DNS setup is one of the quickest ways for emails to land in spam.

5. Warm-Up Services & Seed Accounts

What Are Warm-Up Services?

Warm-up tools send small batches of emails from your accounts to a network of “seed accounts” over a period of weeks. These services often open and interact with your emails—marking them important or replying—to create positive engagement signals for your domain and IP address.

What Is a Seed Account?

A seed account is an email address used to test inbox placement or to help “warm up” sending domains by interacting with incoming mail.

The Challenges

• B2B vs. B2C: If you’re a B2B sender, warm-up services that rely heavily on free consumer inboxes (Yahoo, Gmail, etc.) may not fully simulate stricter business filters like those on Microsoft 365 or Google Workspace. As a result, you can’t fully test your deliverability before your real campaign begins.

• Alternate Approach: Some services use business inboxes owned by their customers to exchange messages. While it’s closer to a real B2B environment, if these inboxes or domains are new or have little reputation, the benefits might be slower to realize.

• Integration & Costs: Securing seed business inboxes for a warm-up pool can be expensive and complicated. Microsoft 365 and Google Workspace often require rigorous verification to integrate fully, and not all warm-up providers are officially verified.

Suggestion: If possible, choose an outreach tool that allows you to configure a gradual warm-up for your domain. At the same time, carefully monitor analytics—opens, replies, and spam complaints—to ensure your outreach remains healthy.

6. Sending Patterns & Automation

Even if your content is perfect, sending too many emails at once can trigger spam flags. ESPs watch for unnatural sending spikes and penalize domains that appear to blast out large volumes rapidly.

Best Practices:

1. Emulate Human Sending
   Use a platform that sends messages at varying intervals, rather than all at once.
2. Gradual Ramp-Up
   For new or freshly warmed domains, start with low volume (5–10 emails per day, per address) and increase slowly over several weeks.
3. Monitor Engagement
   Watch open rates, click-through rates, and replies. High engagement signals good sender behavior to ESPs.

7. Strategies to Solve (or Avoid) Spam Issues

1. Use Similar-Named Domains or Subdomains

• Examples: 

• • yourcompany.com (primary)
  • yourcompany.io / tryyourcompany.com / outreach.yourcompany.com (secondary or subdomains)
• If using a separate domain, add at least a basic landing page to pass DNS checks (like those from MxToolbox). Avoid redirecting to your main domain to protect its reputation.

2. Spread Sending Volume Across Multiple Domains

• Don’t rely on a single domain. Two or more domains, each with a couple of inboxes, can keep sending volume per domain lower and safer. Choose an outreach platform that allows you to send emails from multiple accounts for this purpose.

3. Start Slow with Each Domain

• Gradually build up your sending volume to avoid suspicion.

4. Avoid Spammy Subjects & Content

• Watch out for words like “FREE,” “DISCOUNT,” “ACT NOW,” or excessive punctuation (“!!!”).
• Focus on real value or problem-solving.

5. Keep Messages Short & Personalized

• Recipients are busy. Quickly address a pain point or share a valuable insight.
• Personalize your subject lines and greetings (e.g., reference their role or company) to boost engagement.

6. Use a Scalable Platform

• Choose an outreach tool that allows you to ramp up sending gradually and provides robust analytics (opens, bounces, replies, unsubscribes, and spam complaint reporting).

7. Analyze Your Metrics

• Open Rate: Aim for at least 20% or higher. Below that threshold, your subject lines or domain reputation might be problematic.
• Reply Rate: Aim for at least 5–10% (depending on industry and offering). Low reply rates often indicate message or audience mismatches.

8. Focus on Value, Not Just the Pitch

• Include actionable insights or helpful resources in some outreach. Building trust improves engagement—and reduces spam complaints.

8. Final Suggestions & Best Practices

• Test Everything
  Before sending to your main list, test with personal or colleague accounts (especially on Google Workspace and Microsoft 365 if you’re targeting B2B). Tools like GlockApps, or Email on Acid can also help assess your spam score and check DNS configurations.

• Regularly Check Blacklists
  Use tools like MxToolbox to ensure your domain stays off blacklists.

• Stay Organized
  Use a platform that steadily ramps up sending. Keep track of any DNS updates or changes to your domains.

• Maintain Email List Good Hygiene
  Validate email addresses before sending (using services like Zerobounce) to reduce bounces. High bounce rates harm your reputation.

• Provide Clear Unsubscribe Links
  If recipients can’t easily opt out, they may mark you as spam. Watch unsubscribe rates—anything above 1% could signal a messaging issue. It’s often better to pause, adjust, and then resume your campaign than risk further damage.

• Stay Compliant with Email Regulations
  Laws like CAN-SPAM, GDPR, or CASL mandate certain practices (e.g., including your physical address, an unsubscribe mechanism, etc.). Non-compliance can lead to fines and additional filtering.

• Consider IP Reputation
  If you send via a dedicated IP address, remember that its reputation matters just as much as your domain’s. A high volume of emails from a cold IP can also lead to deliverability issues.

Conclusion

Staying out of the spam folder requires a combination of technical know-how, strategic sending, and genuine, value-focused messaging. By taking the time to set up your domain correctly, warm it up gradually, and prioritize meaningful content for your audience, you significantly increase your chances of landing in the inbox—and converting cold leads into warm opportunities.

Remember: email outreach is about building relationships. If recipients see your emails as helpful rather than intrusive, they’ll welcome them into their inboxes. Good luck with your outreach!