Email Deliverability
SPF, DKIM, DMARC, and 7 more DNS authentication checks.
Email deliverability checks verify that your domain is properly configured to send email. Incorrect DNS records mean your emails land in spam — or get rejected entirely.
#Speed
Takes 2-5 seconds. All checks run inline (no background worker needed). Uses DNS lookups via dnspython.
#What It Checks (10 checks)
| Check | Weight | What It Does |
|---|---|---|
| DMARC | 25 pts | Domain-based Message Authentication — tells receivers what to do with unauthenticated mail |
| SPF | 20 pts | Sender Policy Framework — lists authorized mail servers |
| MX | 15 pts | Mail exchange records — are they valid and reachable? |
| DKIM | 15 pts | DomainKeys Identified Mail — cryptographic signature on emails |
| MTA-STS | 10 pts | Mail Transfer Agent Strict Transport Security — enforces TLS |
| TLS-RPT | 5 pts | TLS reporting — get reports about TLS failures |
| DNSSEC | 5 pts | DNS Security Extensions — protects DNS from tampering |
| BIMI | 5 pts | Brand Indicators for Message Identification — logo in inbox |
| Reverse DNS | 5 pts | PTR record — mail server IP resolves back to your domain |
| DANE | 5 pts | DNS-based Authentication of Named Entities — TLS certificate in DNS |
#Scoring
Each check contributes points based on importance. The total score is weighted out of 110, then displayed as a percentage. DMARC is the most important — without it, SPF and DKIM are significantly less effective.
#API Usage
POST /api/v1/projects/{project_id}/deliverability
Authorization: Bearer pk_...
{
"domain": "example.com"
}#Common Issues
#No DMARC record
Most common issue. Start with a basic DMARC record:
_dmarc.example.com TXT "v=DMARC1; p=none; rua=mailto:dmarc@example.com"Start with p=none to monitor, then move to p=quarantine or p=reject once you're confident legitimate mail passes.
#SPF too many lookups
SPF has a 10-lookup limit. If you use many services (Google, Mailchimp, SendGrid, etc.), you may exceed it. Use include: chains carefully.