Warm up a new domain or IP address

What it means

Mailbox providers like Gmail and Outlook judge senders by their history. A domain registered last week, or a new dedicated IP address, has no history at all. Spammers often use fresh domains and IPs, so providers are careful with them.

"Warming up" means building a good history gradually: starting with a few emails to engaged readers, then increasing the volume over several weeks.

Why it matters

• Sending thousands of emails from a new IP on the first day can lead to temporary blocks, spam placement or a blacklist listing.
• A bad start is hard to undo: the first weeks shape your reputation.
• If you use a shared IP from your provider, the IP is already warm, but your domain still needs to build its own reputation.

Before you start

• SPF, DKIM and DMARC pass for your domain.
• If you have your own server, reverse DNS is set and matches.
• Your list contains only people who asked for your emails recently.
• Unsubscribing is easy, with a one-click header for marketing emails.

How to check

• Send a test email: on the home page, copy your unique test address, send it a normal email from the mailbox or tool you want to check, then open the report. Everything should be green before you begin.
• Use /domain-scanner to check your DNS records, and /blacklists to make sure a new IP is not already listed by a previous owner.

How to warm up

1. Start with your best readers: people who opened or clicked recently. They react well, which builds a positive history.
2. Begin with a small daily volume, for example 50 to 100 emails a day per large provider (Gmail, Outlook, Yahoo).
3. Increase gradually, roughly doubling every few days if results stay good. A typical plan:
   • Week 1: a few hundred emails a day.
   • Week 2: one to two thousand a day.
   • Week 3 and 4: keep increasing until you reach your normal volume.
4. Send regularly, every day or every few days. Long pauses lose some of the progress.
5. Watch the signals after each send: bounces, spam complaints, temporary 4xx errors. Use Google Postmaster Tools and Microsoft SNDS if available.
6. Slow down at the first sign of trouble. If bounces or complaints rise, go back to the previous volume for a few days.

Tips

• Many sending services offer an automatic warm-up for dedicated IPs. Use it if available.
• Do not buy "warm-up" services that exchange fake emails between robot mailboxes: providers detect them.
• Keep transactional emails (receipts, password resets) flowing from the start: they are wanted and help your reputation.

Check that it is fixed

Send a test email from the home page at each step: the report should stay clean. After a few weeks of steady sending, inbox placement should be stable at your normal volume.