You send an email, you’re confident in its quality, but it lands in the spam folder. It’s frustrating, especially when you’re promoting your business, following up with a lead, sending a cold email, or reaching out to webmasters as part of your link-building strategy.

The good news: you can significantly reduce this risk by following a few simple rules.

What is spam?

Spam is an unsolicited email sent without the recipient’s consent. It’s often distributed in bulk to thousands of inboxes and rarely serves a legitimate purpose. It may contain aggressive marketing, phishing attempts, or malicious software.

Email providers like Gmail and Outlook use strict filters to detect and block these messages. These filters don’t just look at the message content. They also analyze the sender’s reputation, message structure, recipient behavior (such as immediate deletions), and technical sending details.

Why does spam still exist?

Because it’s cheap and sometimes profitable - even with low conversion rates. A single reply can make a campaign worthwhile. Most spam is automated, sent using shady tools that dispatch thousands of emails per day. Some spam tries to trick users into revealing personal information, installing malware, or giving access to their accounts.

4 ways to keep your emails out of spam

If you send emails regularly - newsletters, follow-ups, cold outreach - you need to follow best practices to improve deliverability. Here are four key levers, ranked by importance.

1. Use a credible, professional domain

Always send emails from an address tied to your own domain, like firstname@yoursite.com. This builds trust and confirms you're part of a real organization.

Avoid generic addresses like info@, contact@, or worse, no-reply@. These are often flagged as impersonal or automated. A no-reply@ address signals that the sender doesn’t want engagement, which undermines the credibility of your message.

Use addresses that clearly identify a person or specific role, like marie.dupont@yoursite.com, support@yoursite.com, or antoine.hr@yoursite.com. This adds transparency.

Make sure your display name is properly formatted. Instead of vague names like "admin," use something like "Marie Dupont – Customer Service." It humanizes your message.

Also, consider your domain’s age. A brand-new domain with no history may be flagged by spam filters. If you set up a subdomain for email, warm it up slowly with low-volume sends to build a good reputation.

Avoid overly long, technical, or awkward domain names. A short, clean domain improves both readability and credibility.

2. Authenticate your domain

To be recognized as a legitimate sender, your domain needs proper authentication. This involves three DNS records: SPF, DKIM, and DMARC.

SPF (Sender Policy Framework) tells mail servers which IP addresses are allowed to send emails on your behalf. If the IP used to send an email isn’t listed, it may be rejected or flagged.

DKIM (DomainKeys Identified Mail) adds a cryptographic signature to each message. This helps recipients verify that the message wasn’t altered during delivery and really comes from your domain.

DMARC (Domain-based Message Authentication, Reporting & Conformance) links SPF and DKIM. It tells recipients what to do if the message fails either check: let it through, quarantine it, or reject it. DMARC also sends you reports on failed attempts to use your domain.

Together, these three protocols build trust and protect your sending identity.

3. Maintain a clean email list

The quality of your email list is just as important as the content itself. Sending to inactive, incorrect, or unverified addresses hurts your sender reputation. High bounce rates and low open rates trigger spam filters.

Never send emails to contacts you bought or scraped. It’s not only risky legally—it also exposes you to spam traps designed to catch illegitimate senders.

Even with a valid list, regular cleanup is essential. Remove inactive contacts, duplicates, and addresses with no engagement over time. This improves performance and reputation.

Before each campaign, run your list through a verification tool. At Juillet Marketing, we use Lemlist, but tools like NeverBounce and ZeroBounce are also reliable.

Segment your list based on engagement levels. There’s no reason to send the same email to a long-time inactive contact and a new subscriber. This targeting improves relevance, reduces unsubscribes, and keeps you out of spam.

4. Avoid spam-like language and formatting

Content matters. Certain words are red flags to spam filters—like “free,” “urgent,” or “click here.” Excessive caps, exclamation points, or flashy formatting can also hurt you.

Keep your design clean. Maintain a good text-to-image ratio, and avoid using too many bright colors or large images.

Always include a clear unsubscribe link, even in cold outreach. Giving recipients control over their subscription helps you avoid complaints.

Finally, monitor your domain’s reputation. Free tools like Google Postmaster Tools, Mail-Tester, and MxToolbox let you track how mail providers perceive you.

Conclusion

Delivering email successfully isn’t about luck. It’s about following proven technical and editorial practices. By securing your domain, personalizing your outreach, and keeping your lists healthy, you greatly increase the chances that your message will be seen—and not ignored.

Respecting your recipients is what keeps your email strategy sustainable.

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