Solutions
Free Email Warmup — Not Needed On Mails.ai
You do not need a free email warmup tool on Mails.ai, because there is nothing to warm. Your agent sends from a shared rail we have already warmed — a real record of transactional sends, low complaints and verified authentication — and it inherits that from its first message. There is no seed network, no schedule to run, and no warmup subscription. The free tier is $0 for 3,000 events a month.
Why warmup tools exist — and why there is nothing to warm here
Traditional email warmup tools exist to solve one problem: a new sending IP or domain with zero history looks suspicious to spam filters. To get past that, senders ramp volume over weeks and mail seed networks to manufacture engagement signals. It is slow, fragile, and yours to manage.
Mails.ai removes the problem instead of selling you a tool for it. Your agent sends from your workspace subdomain — agent@yourworkspace.mails.ai — on a shared rail that is already warm: a real record of transactional sending, low complaint rates and verified authentication. Your first message goes out on that record. There is no ramp to wait through.
What happens when you bring your own domain
Sending as notifications@yourapp.com is different, and this is where most warmup marketing is dishonest. A brand-new domain has no standing of its own, and no vendor can create one for you — mailbox providers weight real opens, replies and complaints from real people. Seed-network mail builds a pattern, not a reputation.
What you actually get:
- A DKIM keypair generated for your domain automatically — you publish one DNS record
- Delivery over mail servers we own and keep warm, rather than a cold box rented this morning
- SPF guidance that merges with your existing record instead of replacing it, so your current email keeps working
- No nameserver move, and no seed network anywhere in the path
Your domain's own standing then builds the only way it can: with the real mail your product sends. One limit worth knowing before you set this up — mail from a custom domain cannot reach Outlook or Hotmail recipients yet. Mail from your mails.ai subdomain reaches them normally.
# Add your domain (any paid plan) — we return the DNS records to create
curl https://api.mails.ai/v1/domains \
-H "Authorization: Bearer $MAILS_API_KEY" \
-H "Content-Type: application/json" \
-d '{"domain": "mail.yourapp.com"}'
# Publish the DKIM record at your registrar, then check status
curl https://api.mails.ai/v1/domains/dom_123 \
-H "Authorization: Bearer $MAILS_API_KEY"
# {
# "id": "dom_123",
# "domain": "mail.yourapp.com",
# "status": "verifying", // pending -> verifying -> verified
# "provider": "ownmetal",
# "dns_records": [
# { "type": "TXT", "host": "dkim._domainkey.mail.yourapp.com",
# "purpose": "dkim", "required": true, "verified": false }
# ],
# "fail_reason": "dkim record missing or mismatched (dkim._domainkey.mail.yourapp.com)"
# }What it costs
Nothing, to start. The free tier is $0/mo and covers 3,000 events and one agent on your workspace subdomain — warm rail included, because that is simply how the product sends. Sending from your own domain is on the paid plans, from $20/mo, which also lifts you to five agents. Agents that do not have a domain yet start on their own AI email address and need no warmup at all.
Want reputation isolated from the shared pool entirely? A dedicated IP is available on request on the Scale plan. It is worth being blunt about when that helps: a dedicated IP only earns a reputation if you give it steady volume, so below roughly a few hundred thousand messages a month you are usually better off on the warm shared rail.
Frequently asked questions
Do I need a separate email warmup tool?
No. Your agent sends from your workspace subdomain on a rail that already has a sending record, so its first message goes out on warm infrastructure. There is no seed list to build, no ramp schedule to run, and no third-party warmup service to buy.
Is email warmup really free on Mails.ai?
There is nothing to charge for. Warm shared infrastructure is how the product sends by default, on every tier including the free one ($0/mo, 3,000 events). There is no warmup add-on and no seed-network fee.
What about my own domain — does that get warmed automatically?
No, and we would rather say so. A brand-new sending domain has no history of its own, and nobody can manufacture one for you: mailbox providers weight real opens, replies and complaints from real recipients. What you do get is a per-domain DKIM key generated automatically, and delivery over mail servers we own and keep warm. The domain's own standing then builds with your real traffic. Anything that promises to warm your domain for you with seed mail is building a pattern, not a reputation.
Does email warmup work for cold outreach on Mails.ai?
No — cold outreach is refused by the API, not just discouraged in the policy. This is for transactional and agent-initiated email: notifications, reply threads, and agent-to-human conversation. That refusal is exactly why the shared rail stays deliverable for everyone on it.
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$ npm install @mailsai/sdk