Email Deliverability Checker

Why it matters: SPF tells receiving servers which IPs are authorized to send on your behalf. Without it, your emails are more likely to be flagged as spoofed.

What to do: Add an SPF TXT record to your domain DNS. Include all services that send email for your domain (e.g., your ESP, transactional email service, CRM).

Why it matters: DKIM adds a cryptographic signature to your emails, proving they have not been tampered with in transit. Unsigned emails lose trust with major inbox providers.

What to do: Generate a DKIM key pair through your email service provider and publish the public key as a DNS TXT record. Verify signing is active on test sends.

Why it matters: DMARC ties SPF and DKIM together and tells receivers what to do with unauthenticated mail. Without it, spoofers can send email that appears to come from your domain.

What to do: Start with a DMARC policy of p=none to monitor, then move to p=quarantine or p=reject once you confirm all legitimate sources are authenticated.

Why it matters: On a shared IP, another sender's poor practices can damage your reputation. A dedicated IP means your deliverability depends only on your own behavior.

What to do: Request a dedicated IP from your ESP if you send more than 50,000 emails per month. For lower volumes, a reputable shared IP pool is usually sufficient.

Why it matters: Frequent changes to your sender name or address confuse recipients and spam filters. Consistency builds recognition and trust over time.

What to do: Pick a "From" name and address for each email type (marketing, transactional) and stick with it. Avoid using no-reply addresses for marketing.

Why it matters: Sending to addresses that consistently bounce signals to ISPs that you do not maintain your list, which lowers your sender reputation.

What to do: Configure your ESP to automatically suppress hard bounces after the first occurrence. Review soft bounces weekly and remove addresses that fail repeatedly.

Why it matters: Double opt-in confirms the subscriber actually owns the email address. It reduces typos, spam traps, and complaint rates significantly.

What to do: Enable confirmed opt-in on all signup forms. Send a simple confirmation email with a single link to verify the subscription.

Why it matters: If unsubscribing is difficult, recipients will mark your email as spam instead. Spam complaints directly damage your sender reputation.

What to do: Include a one-click unsubscribe link in every email. Add a List-Unsubscribe header so email clients can show their own unsubscribe button.

Why it matters: Purchased lists contain spam traps, inactive addresses, and people who never consented. Sending to them can get your domain blacklisted.

What to do: Build your list organically through opt-in forms, lead magnets, and content. Remove any contacts whose origin you cannot verify.

Why it matters: Sending to disengaged subscribers lowers your open rates, which ISPs use as a signal of sender quality. Low engagement drags down deliverability for your entire list.

What to do: Segment your list by last engagement date. Send more frequently to active subscribers and run re-engagement campaigns for those inactive for 90+ days.

Why it matters: Emails that are mostly images with little text trigger spam filters. Some email clients block images by default, leaving recipients with a blank email.

What to do: Aim for at least 60% text and no more than 40% images. Always include alt text on images and ensure the email is readable without images loaded.

Why it matters: Certain words and phrases are strongly associated with spam. Overusing them increases the probability of landing in the junk folder.

What to do: Avoid words like "free," "guaranteed," "act now," and "no obligation" in subject lines and body copy. Write naturally and focus on value.

Why it matters: Over half of all emails are opened on mobile devices. Non-responsive emails are hard to read and lead to lower engagement and higher unsubscribes.

What to do: Use a single-column layout with a max width of 600px. Test every template on both iOS and Android email clients before sending.

Why it matters: Personalized emails see higher open and click rates. Generic emails that look like mass blasts get less engagement, which hurts deliverability over time.

What to do: At minimum, use the recipient's first name. Better yet, personalize content based on past purchases, browsing behavior, or stated preferences.

Why it matters: Misleading or vague subject lines increase spam complaints. Clear subject lines set accurate expectations and improve open rates.

What to do: Write subject lines that accurately describe the email content. Keep them under 50 characters. Avoid all caps, excessive punctuation, and clickbait.

Why it matters: Erratic sending patterns — silence for weeks followed by a burst of emails — look suspicious to ISPs and can trigger throttling or filtering.

What to do: Set a regular cadence (e.g., weekly newsletter, monthly digest) and stick to it. Subscribers should know roughly when to expect your emails.

Why it matters: Sending a large volume from a new IP or domain with no reputation is a strong spam signal. ISPs need to see a gradual build of trust.

What to do: Start with small volumes (100-500 per day) to your most engaged subscribers and increase by 20-30% daily over 2-4 weeks.

Why it matters: Sudden spikes in send volume trigger ISP rate limits and can damage your reputation. Monitoring helps you catch anomalies before they cause problems.

What to do: Set up alerts for send volume changes greater than 30% from your baseline. Review sending logs daily during campaign launches.

Why it matters: Subscribers who have not opened or clicked in 6-12 months are dead weight. They lower your engagement metrics and may turn into spam traps.

What to do: Send a final re-engagement email after 90 days of inactivity. If there is no response, suppress or remove the address from your active list.

Why it matters: Mixing transactional emails (receipts, password resets) with marketing on the same IP or domain means a marketing reputation hit can delay critical transactional emails.

What to do: Use separate subdomains and, ideally, separate IPs for transactional and marketing email. This isolates reputation for each stream.