Glossary
Email Deliverability
Getting your email into the inbox, not the spam folder
What is Email Deliverability?
Email deliverability is the measure of whether your emails actually arrive in recipients' inboxes. An email can be "delivered" to a mail server yet still land in the spam folder - or be silently rejected. Deliverability covers the whole journey from your sending server to the reader's inbox.
Mailbox providers like Gmail and Microsoft decide where each message goes based on your sender reputation, authentication records, content, and recipient engagement. Since 2024, major providers require bulk senders to authenticate with SPF, DKIM, and DMARC, making deliverability a technical requirement rather than a nice-to-have.
What Affects Deliverability
- Authentication - SPF, DKIM, and DMARC records published in DNS prove your mail is legitimate
- Sender reputation - Your domain and IP build a track record with mailbox providers
- List hygiene - Bounces and spam complaints from stale lists damage your reputation
- Engagement - Opens and replies help; mass deletions and "mark as spam" hurt
- Content and volume - Sudden volume spikes and spammy content trigger filters
Improving Deliverability in Practice
- Publish SPF and DKIM - Authorize and cryptographically sign your outgoing mail
- Deploy DMARC - Tell receivers what to do with mail that fails authentication, and get reports back
- Monitor reports - DMARCsimple by CCMS turns raw DMARC reports into clear dashboards so you can see who is sending as your domain and fix failures
- Warm up gradually - Increase sending volume slowly on new domains or IPs
- Clean your lists - Remove unengaged addresses and honor unsubscribes immediately