Solutions
Free Email Warmup — Automatic, Built Into Mails.ai
Free email warmup on Mails.ai is automatic: when your sending domain goes live, SES manages its reputation ramp with no manual schedule, no CSV of seed addresses, and no separate warmup service to pay for. The shared rail is already warm; new custom domains ramp over roughly 14 days while real sends go out. Metered tier starts at $0/mo — you pay $0.001 per send and nothing until you send.
Why traditional warmup tools exist — and why you don't need one here
Traditional email warmup tools exist to solve a single problem: a new sending IP or domain with zero history looks suspicious to spam filters. To overcome that, senders manually ramp volume over weeks, sending to seed networks to build artificial engagement signals. It's slow, fragile, and something you have to manage yourself.
Mails.ai sidesteps the problem architecturally. The shared sending rail is already warmed — it has a track record of real transactional sends, low complaint rates, and verified domain authentication. When you send through it, your mail inherits that reputation from the first message.
Custom domain warmup — automatic, managed by SES
If you send from your own custom domain (e.g. notifications@yourapp.com), that domain needs its own reputation ramp before spam filters treat it as trusted. On Mails.ai, that ramp is automatic:
- SES manages the configuration set and reputation build for your domain
- Sends route through both the warming context and the shared pool during the ramp
- No seed lists, no manual schedule, no third-party warmup service
- Domain status is visible at
/dashboard/domains
The ramp runs alongside real sends — your agents can start sending on day one. The warmup period is roughly 14 days for a new domain.
# Add your domain — warmup starts automatically after DNS verification
curl https://api.mails.ai/v1/domains \
-H "Authorization: Bearer $MAILS_API_KEY" \
-H "Content-Type: application/json" \
-d '{"domain": "yourapp.com"}'
# Check warmup / reputation status
curl https://api.mails.ai/v1/domains/yourapp.com \
-H "Authorization: Bearer $MAILS_API_KEY"
# {
# "domain": "yourapp.com",
# "status": "warming", // warming → active after ~14 days
# "reputation": 0.74, // 0–1 score, builds over time
# "dns_verified": true
# }Pricing: free to start, $0.001 per send
The Metered tier has no monthly minimum. You pay $0.001 per outbound message and $0.002 per inbound. Warmup is included. There is no warmup-tool subscription to add, no seed-network fee, and no upfront commitment — you can connect a domain and start sending today.
Frequently asked questions
Do I need a separate email warmup tool?
No. Mails.ai handles warmup as part of the sending infrastructure. New custom domains ramp automatically via SES configuration sets — you don't configure a seed list, schedule a warmup sequence, or pay for a third-party warmup service. The process runs alongside real sends from day one.
Is email warmup really free on Mails.ai?
Yes. The warmup process — managing your sending reputation through the initial ramp — is included in all tiers. The Metered tier has no monthly minimum: you pay $0.001 per message sent and $0.002 per message received, and nothing else until you send. There is no warmup surcharge.
How long does the warmup take?
New custom domains typically ramp over 14 days. During that window, SES routes sends through both the dedicated reputation context and the shared pool to build a clean track record. You can see status in /dashboard/domains. There is no action required on your side.
Does email warmup work for cold outreach on Mails.ai?
No — cold outreach is prohibited by the acceptable-use policy and blocked at the API. Warmup here is for transactional and agent-initiated email: notification sends, reply-thread management, and AI-agent-to-human communication. That constraint is why the shared rail stays deliverable for everyone on it.
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$ npm install @mailsai/sdk