StopBouncingHow to Improve Your Email Deliverability
Getting an email into the inbox — not the spam folder — requires getting five things right: list quality, authentication, sender reputation, engagement, and infrastructure. This guide covers all five.
The Five Pillars of Email Deliverability
List Quality
Verify your listA clean email list is the foundation of deliverability. Remove invalid, disposable, and undeliverable addresses before every send. Aim for a bounce rate below 0.5% per campaign.
Email Authentication
Check your SPFSPF, DKIM, and DMARC tell inbox providers that your emails are genuinely from your domain and haven't been tampered with. Missing authentication is a top cause of spam folder placement.
Sender Reputation
Reduce bouncesGmail, Outlook, and other providers assign a reputation score to your sending domain and IP. Bounces, spam complaints, and sudden volume spikes all damage your reputation — and are hard to recover from.
Engagement Signals
Clean inactive subscribersInbox providers track whether recipients open, click, and reply to your emails. High engagement signals legitimate and wanted mail — improving placement for your entire list, not just the active segment.
Infrastructure
Check DNS recordsYour sending IP, domain age, and email volume consistency all influence deliverability. New senders need to warm up gradually — sending 1,000 emails on day one to a fresh IP is a reputation risk.
Email Authentication Checklist
These three DNS records are required for reliable inbox placement in 2026.
Declares which mail servers are authorized to send email from your domain. A missing SPF record is a common cause of spam folder placement.
Adds a cryptographic signature to every outgoing email that proves the message wasn't altered in transit. Required by Gmail and Yahoo since 2024.
Ties SPF and DKIM together and tells receiving servers how to handle unauthenticated messages — reject, quarantine, or monitor. Also required by Gmail for bulk senders.
Email Deliverability FAQ
What is email deliverability?
Email deliverability is the ability to successfully land an email in the recipient's primary inbox — not their spam folder, promotions tab, or rejection queue. Deliverability is influenced by your list quality, sender reputation, authentication setup, email content, and engagement rates.
Why are my emails going to spam?
The most common causes are: a high bounce rate (invalid addresses), missing SPF/DKIM/DMARC records, a poor sender reputation (caused by past spam complaints or sudden volume spikes), poor list quality (sending to unengaged subscribers), or content that triggers spam filters.
How do SPF, DKIM, and DMARC improve deliverability?
SPF (Sender Policy Framework) tells receiving servers which mail servers are authorized to send email from your domain. DKIM (DomainKeys Identified Mail) adds a cryptographic signature to your messages proving they haven't been altered. DMARC (Domain-based Message Authentication, Reporting & Conformance) ties SPF and DKIM together and tells servers what to do with unauthenticated mail. All three are required for modern inbox placement.
What bounce rate is considered good?
A hard bounce rate below 0.5% per campaign is considered excellent. Below 2% is acceptable for most platforms. Above 2%, most email service providers will issue warnings, suspend accounts, or require list cleaning before you can send again.
How does email list verification improve deliverability?
Verifying your list removes invalid, expired, disposable, and unverifiable addresses before they cause hard bounces. Fewer bounces means a better reputation with inbox providers — which means better placement for every email you send, including to your engaged subscribers.
Free Deliverability Tools
SPF & DKIM Checker
Verify your email authentication records.
DMARC Checker
Check your DMARC policy configuration.
MX Record Lookup
Verify your domain's mail server records.
Email Verification
Clean your list before sending.
Reduce Bounce Rate
Practical guide to bounce management.
Bulk List Cleaning
Remove invalid addresses from entire lists.
Start With What Matters Most — List Quality
Verify your email list and cut your bounce rate to under 0.5%. 100 free credits on signup.