From MX record to inbox delivery.
JoltMx is a multi-stage email pipeline. Here is what happens when someone sends an email to your domain.
SMTP receipt
Your MX records point to JoltMx. Our SMTP ingress servers accept the connection, negotiate TLS, and receive the message. The raw .eml is immediately stored in object storage with a SHA-256 hash for integrity.
- STARTTLS and implicit TLS on ports 25 and 465
- Recipient validation at SMTP time
- Immediate rejection of unrecognized domains
Threat screening
Before authentication analysis, JoltMx checks the connecting sender IP against Spamhaus DNS blocklists. Blocklisted sources are rejected immediately during SMTP and never move deeper into the pipeline.
- Spamhaus DNSBL lookup at MAIL FROM stage
- Immediate rejection of known abusive source IPs
- Cached lookup results for low-latency decisions
Authentication checks
SPF records are evaluated against the sending IP. DKIM signatures are verified. DMARC policy is looked up and alignment is checked. If the domain publishes a reject policy, the message is rejected.
- SPF, DKIM, and DMARC evaluation
- Upstream Authentication-Results parsing
- Per-message audit events with full detail
Route matching
Each recipient address is independently matched against your routing rules. Exact matches take priority over catch-all patterns. The matched route determines the action: forward, store, or reject.
- Per-recipient evaluation
- Priority-based rule resolution
- Mail-from sender filtering applied here
Reliable forwarding
Messages are forwarded to verified destinations through our own outbound delivery engine with SRS (Sender Rewriting Scheme) for SPF alignment. Temporary failures are retried with exponential backoff.
- SRS for SPF bounce path alignment
- Per-attempt logging with SMTP response codes
Every stage, recorded per message.
That whole pipeline is captured for each message you receive — receipt, the SPF/DKIM/DMARC verdict, the spam scan, which rule matched, and a delivery result for every recipient.
Start routing mail
in minutes.
Point your MX records at JoltMx. Add a domain. Create your first rule. Done.
No credit card required · Free tier stays free