Email infrastructure for builders
Per-tenant DKIM. ARC sealing. Pre-send AI scoring. One API. Self-hostable. Free up to 1,000 emails a month.
INTEGRATE
POST a JSON. We sign, route, deliver. Same API for transactional, marketing, and per-recipient send-time.
curl -X POST https://api.sendbolt.com/api/v1/transactional/send \ -H "Authorization: Bearer $MP_KEY" \ -H "Content-Type: application/json" \ -d '{ "to": "alice@example.com", "subject": "Welcome to Acme", "body_text": "Hi Alice, you are in.", "bounce_risk_check_enabled": true }' # { "status": "queued", "message_id": "tx-1778..." }REPUTATION
Spam-score + bounce-risk + send-time AI in one call. Cancel sends that will burn your domain. Reroute the rest to their best hour.
# POST /api/v1/send-quality/preview
# Run this BEFORE you send — get the verdict
# spam + bounce + send-time in one call.
curl -X POST https://api.sendbolt.com/api/v1/send-quality/preview \
-H "Authorization: Bearer $MP_KEY" \
-H "Content-Type: application/json" \
-d '{
"subject": "Welcome to Acme",
"body_text": "Hi Alice, ...",
"from_domain": "acme.com",
"recipient_email": "alice@gmail.com",
"has_list_unsub": true
}'
# {
# "quality": 8.5,
# "verdict": "good",
# "spam_score": 9.0,
# "bounce_risk": 0.1,
# "best_send_hour_utc": 14
# }PIPELINE
Every send walks the same signed path. Per-tenant DKIM key, ARC seal across forwards, 11-tier auto-warmup, suppression gate. We don't lose mail because we don't lose track of it.
POST /send
Auth + scope
Pre-send AI
Spam · bounce · time
DKIM + ARC
Per-tenant key
11-tier gate
Per-domain cap
MX delivery
Auto-pause @3%
Recipient inbox
Tracked
CONTROL
The console SendGrid charges Enterprise for. Per-worker health, DNS drift, bounce categories, schema state, send-quality trend — one page.
We optimise for one number: the percentage of your mail that arrives in the Primary tab. Everything else — warmup curves, DKIM rotation, ARC sealing, suppression discipline — exists to move that number.
OWNERSHIP
Multi-tenant SaaS by default. Self-hostable on your own VPS. Bring your own dedicated IP pool. GDPR + data-residency built in. No lock-in.
Apache-style open architecture. Deploy on your VPS in 20 minutes.
Dedicated IPs across multiple ASNs. Warm them on our infrastructure.
EU + India + US shards. Audit log streaming to your own SIEM.
“We migrated off SendGrid and cut cost 4× while improving deliverability. The pre-send spam-score API paid for the switch on day one.”
PRICING
Every tier ships DKIM rotation, ARC, and the AI scoring API. You only pay for volume.
Free
$0/ mo
1,000 / month
Side projects + indie hackers
Starter
$29/ mo
50,000 / month
3 domains · 5 templates
Pro
$99/ mo
250,000 / month
Unlimited · SSO
Scale
$399/ mo
1.5M / month
Dedicated IPs · DPA
No credit card required. 14-day trial on every paid tier.