How to Warm Up a New Domain for Transactional Emails

When you start using AutoSend to send transactional emails, you’re likely using a freshly connected domain or subdomain. That domain might be perfectly configured with verified DNS, working SPF, DKIM, and DMARC. But to mailbox providers like Gmail or Outlook, it’s brand new. They don’t yet know your sending behavior or your engagement quality.

If you start sending thousands of password resets or verification emails right away, filters may flag your messages as suspicious. This is where domain warm-up comes in.

What is domain warm-up?

Domain warm-up is the process of gradually increasing the volume of emails you send through a new domain or IP.

The goal is to show mailbox providers that you’re a legitimate sender who sends to real, engaged users and not a spammer blasting to thousands of unverified addresses.

Think of it like training mode for your domain. Every email you send builds reputation, and with each positive signal (like opens, clicks, or successful deliveries), your domain earns trust.

Why warm-up matters when you start using AutoSend

When you connect a new domain in AutoSend, the system authenticates it automatically with SPF, DKIM, and DMARC settings. Technically, you’re ready to send.

But reputation is not built overnight. Without a warm-up phase:

• Your first few campaigns might land in spam or promotions tabs.

• You could experience slow delivery or throttling by major inboxes.

• Your sender reputation could drop before it even starts.

Warming up allows AutoSend’s sending infrastructure and your domain to build a positive reputation together. It’s how you establish consistent inbox placement from day one.

Before you start warming up

Make sure these basics are covered before sending your first email:

1. Use a dedicated subdomain for transactional emails
Instead of sending from your root domain, use something like notify.yourdomain.com. This separates transactional emails from marketing traffic and keeps your main domain reputation safe.

2. Verify your domain in AutoSend
Go to your AutoSend dashboard and complete domain verification. This ensures your SPF and DKIM records are valid and the domain is ready for sending.

3. Send only to real users
If you already have active customers or verified users, start with them. Don’t test with random or inactive addresses. High bounces in the first week can severely hurt your reputation.

Step-by-step warm-up plan for AutoSend users

Week 1: Start small and consistent

Send around 20 to 50 transactional emails per day.
Examples: sign-up confirmations, test password resets, or account alerts.

AutoSend will automatically log each email’s delivery, bounce, and open rate. Keep an eye on these metrics from your dashboard.

Week 2: Slowly increase the volume

If your first week looks healthy (no major bounces or spam complaints), double your daily sending volume. Maintain the same schedule. Sending consistently every day is more important than sending large batches.

Week 3–4: Ramp up to normal usage

You can now start sending more real transactional traffic.
Increase gradually by 25–30 percent every few days. Watch your logs in AutoSend; if you notice rising bounce or delay rates, hold the volume steady until things stabilize.

After a month: Reach steady state

Once you’ve reached your normal email volume and maintain stable deliverability, your domain is officially “warmed up.” From here on, consistent performance and low bounce rates will keep your reputation strong.

What AutoSend tracks to help during warm-up

AutoSend provides detailed logs and metrics that are essential during warm-up:

• Delivery rate – How many emails successfully reach the inbox.

• Bounce reports – Identify invalid addresses early.

• Latency – How fast messages are accepted by recipient servers.

• Spam or complaint signals – See if users flag your messages.

You can access all these insights directly in your AutoSend dashboard.

Common mistakes to avoid

• Sending too much, too soon: The most common mistake is sending large volumes right after connecting your domain to AutoSend. When a brand-new domain suddenly starts sending thousands of emails, mailbox providers interpret that as suspicious behavior. It resembles what spammers do — appear out of nowhere and flood inboxes. Start small, send consistently, and increase volume gradually. This signals stability and helps mailbox algorithms learn to trust your sending pattern.

• Testing with fake or inactive email addresses: It might be tempting to bulk-test your setup using random or made-up addresses, but that’s a fast way to ruin your domain’s reputation. Every bounce or invalid recipient negatively affects your trust score. Instead, test with verified accounts — your own team, colleagues, or users who actually exist. In AutoSend, you can track every delivery and bounce in your logs, so you don’t need to risk fake tests.

• Ignoring soft bounces and temporary errors: Soft bounces often get dismissed as “minor” issues, but they’re valuable signals. They usually indicate that the receiving server is temporarily limiting your volume or delaying acceptance until it trusts you more. If you keep pushing the same volume without addressing it, providers may start blocking you completely. Watch for patterns in your AutoSend delivery logs. If you see repeated soft bounces, slow your sending rate or pause the ramp-up until things stabilize.

• Mixing marketing and transactional messages: During warm-up, focus only on true transactional emails — password resets, account verifications, or receipts. Mixing promotional content like discounts or product updates confuses spam filters and can damage your domain’s reputation before it’s even established. Always send marketing campaigns from a separate subdomain, for example, updates.yourdomain.com, while keeping transactional traffic on notifications.yourdomain.com. AutoSend supports multiple verified domains and subdomains, making this easy to manage.

• Not checking AutoSend logs or monitoring metrics: One of the biggest advantages of AutoSend is visibility — you can see exactly what’s happening with every message you send. Ignoring this data during warm-up is like flying blind. Your logs show delivery success, bounces, latency, and user engagement. Checking them regularly helps you identify potential issues early. If you notice unusual delays, high bounces, or authentication errors, it’s a sign to pause and correct the setup before scaling further.

• Stopping activity too soon: Some users complete their warm-up successfully and then stop sending emails for several weeks. That can actually cause your domain reputation to cool down again. Mailbox providers value consistent patterns, so when you stop sending, your “trust history” begins to fade. If you anticipate downtime, keep a minimal amount of activity running — even a few test emails every few days through AutoSend is enough to maintain domain freshness.

How long should warm-up take?

For most AutoSend users, it takes around 2 to 3 weeks to reach full volume safely. Smaller teams or products with lower email traffic can complete it in less time. If your monthly sending volume is less than 10,000 emails then it should be 1 to 2 weeks.

The key is not speed but consistency. A slow and steady ramp-up gives mailbox providers the confidence they need to treat your messages as trusted communication.

Maintaining your sender reputation

Once your domain is fully warmed up:

• Keep sending regularly — inactivity can reset reputation.

• Monitor your bounce rate weekly.

• Use AutoSend’s logs to ensure your authentication remains valid.

• Avoid sudden spikes in email volume.

Treat your domain’s reputation like uptime monitoring. It’s ongoing maintenance, not a one-time task.

Warming up your domain is one of the most important things you can do when starting out with AutoSend or any other email service provider.

It’s not complicated, just intentional. Start small, be consistent, and use the detailed logs AutoSend provides to monitor every stage. Within a few weeks, your emails will reach inboxes faster, avoid spam filters, and stay reliable — exactly what transactional emails are meant to do.

You’ve read this far, so here’s a quick tip: encourage users to reply to your emails to boost your domain reputation.

Frequently Asked Questions

Do I need to warm up my domain after connecting it to AutoSend?

Yes. Even if your domain is verified in AutoSend, mailbox providers don’t yet trust it. Warming up builds a positive reputation and prevents your emails from being flagged or delayed.

2. How long should I warm up before sending full volume?

It usually takes around 3 to 4 weeks for most AutoSend users to reach steady-state volume. The exact time depends on your daily email traffic and engagement rates.

3. Should I use my main domain or a subdomain for transactional emails?

Use a subdomain like notifications.yourdomain.com. AutoSend makes this easy to configure during domain setup. It isolates your transactional traffic from marketing or newsletter emails.

4. How can I monitor my progress during warm-up?

Your AutoSend dashboard shows real-time logs for every email: delivery status, bounces, latency, and engagement metrics. You can use this data to track how your warm-up is progressing and adjust accordingly.

5. What happens if I send too many emails too quickly?

Mailbox providers may throttle or block your messages, causing slow delivery or spam placement. It can also lower your domain reputation, making recovery harder later.

6. Can I warm up multiple domains in AutoSend?

Yes. If you manage multiple products or environments, you can verify and warm up separate subdomains individually inside your AutoSend account. Each one will build its own reputation.

7. What if I stop sending emails for a few weeks after warming up?

If your domain goes inactive for a long time, reputation may start to decay. When you resume, repeat a shorter warm-up phase by sending smaller volumes again for a few days.