Calentamiento de dominio e IP
When a new domain or IP starts sending email, receiving servers have no history to judge whether it's legitimate. Warmup is the process of progressively increasing volume to build good reputation. Skipping it is the #1 mistake new senders make.
Receiving servers (Gmail, Outlook, Yahoo) use IP and domain reputation as the main input to decide inbox or spam. If a new domain sends 100,000 emails on day one, that's a typical spam signal.
Warmup is the process of gradually increasing volume — usually over 4-8 weeks — so receivers accumulate positive data about your sender: opens, clicks, replies, low spam signals.
It applies to both: new domains (you created a domain to send email) and dedicated IPs (you were given a fresh IP or switched providers).
Real example
Semana 1: 200/día → Semana 2: 1.000/día → Semana 3: 5.000/día → Semana 4: 25.000+/día
Día 1-7Kickoff (to your engaged subscribers)
Start with 100-500 emails/day to your most engaged subscribers (those who opened in the last 30 days). Focus: real opens and clicks.
Día 8-14Conservative ramp-up
Progressively double volume. 1,000 → 2,000/day. Keep prioritizing recent engagement.
Día 15-21Including less engaged subscribers
You reach 5,000-10,000/day. Start adding subscribers with engagement from the last 90 days.
Día 22-30Target volume
You reach your operation's normal volume. Maintain a consistent cadence, without sharp spikes.
Steps in order. Skipping one usually leads to problems that take days to diagnose.
Remove historical hard bounces, role-based addresses if your business allows it, and subscribers with no activity in 12+ months. A dirty list is the worst way to start.
Tip: If you've never cleaned it, that cleanup can shrink your list by 20-40%. It's worth it.
Sending without authentication during warmup is an accelerant for ending up in spam. All three need to be OK before you start.
The first sends go to your best contacts: those who opened in the last 30 days. Their positive behavior (opens, clicks, replies) is the signal receivers need.
1,000/day consistently is better than 5,000 on Monday and nothing the rest of the week. Receivers value a regular pattern.
Gmail, Outlook, and Yahoo behave differently. If you see a specific drop in one (postmaster.google.com / Microsoft SNDS), adjust that segment without affecting the rest.
Save day-by-day metrics: opens, clicks, bounces, complaints. That baseline helps you for the rest of the operation.
It's one of the most frequent causes of deliverability problems. Sending 50,000 emails on day 1 from a new domain greatly increases the risk of landing in spam.
How to fix it: Respect the minimum 4 weeks. If your target volume is high, you can extend to 6-8.
If you send to all your contacts without segmenting, you include old subscribers who don't remember signing up. Bounces and complaints spike.
How to fix it: Start only with recently engaged subscribers. Add less engaged ones gradually in week 3-4.
If on day 5 you see a high bounce rate, it's not the time to pause for two weeks. It's time to review the list, not stop.
How to fix it: Quick diagnosis and correction. Pausing breaks the pattern you're building.
A purchased list or one unused for 2 years generates extremely high bounce and complaint rates. It burns fresh reputation instantly.
How to fix it: Only use opt-in, recent, clean lists. Period.
Three ways to check — from your terminal or online tools. If all of them return OK, you're done.
Google Postmaster
postmaster.google.com
Official Gmail metrics: IP/domain reputation, spam rate, DMARC pass rate.
Microsoft SNDS
sendersupport.olc.protection.outlook.com/snds/
IP reputation on Microsoft networks (Outlook, Hotmail, Live).
arrobaMail Reports
Panel > Reportes > Reputación
Consolidated deliverability view by provider + early alerts.
How arrobaMail handles it
arrobaMail assists warmup from the dashboard: we suggest a schedule based on your target volume, guide you to work first with your most engaged contacts, and monitor reputation across major providers.
At least 4 weeks for medium volumes (up to 50k/day). For larger volumes (100k+/day), it's usually 6-8 weeks. The higher the target, the more gradual the ramp-up should be.
Not for the IP — the shared IP already has reputation built from sending by many other clients. You do need to warm up the domain if it's new or if you've never sent with it.
Yes, the domain "becomes new again" from receivers' perspective once IPs and servers change. A shortened 2-3 week warmup is recommended.
Open rate > 20%, click > 2%, bounce < 2%, complaint < 0.1%. If any of these go off track, pause the ramp-up and review segmentation or content before increasing volume further.
They're parallel but distinct processes. Receivers measure reputation for both. If you only renew the IP (provider change), the domain keeps its reputation. If you renew both, you warm up both together.
Sender Policy Framework
Lista blanca de servidores autorizados a enviar mail con tu dominio.
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