How do I use dedicated IPs with a transactional email service?

Using dedicated IPs with a transactional email service usually means you send your app’s emails through IP addresses that belong only to you, instead of sharing reputation with other senders.

Here’s the typical process:

1. Buy or request dedicated IPs

Your email provider will usually offer dedicated IPs as an add-on. You may get:

• One dedicated IP
• Multiple dedicated IPs for higher volume or segmentation

2. Warm up the IP

A brand-new dedicated IP has no sending reputation, so you should start with low volume and gradually increase over days or weeks.

Typical warm-up approach:

• Day 1: send to your most engaged users only
• Increase volume gradually
• Avoid sudden spikes

This helps mailbox providers like Gmail and Outlook trust your sending.

3. Authenticate your sending domain

Set up email authentication so providers know your emails are legitimate:

• SPF
• DKIM
• DMARC (recommended)

Also make sure your From domain matches your authenticated domain.

4. Route transactional email through the dedicated IP

In your service/provider, you usually:

• Create an IP pool or assign the dedicated IP to a sender/domain
• Configure your app/API to send through that pool
• Keep transactional emails separate from marketing if possible

5. Monitor reputation and deliverability

Track:

• Bounce rate
• Spam complaints
• Open/click rates
• Inbox placement
• IP reputation

If the IP gets a bad reputation, deliverability can suffer.

6. Maintain good sending practices

Dedicated IPs work best when your email quality is high:

• Send only requested/expected transactional emails
• Keep lists clean
• Remove invalid addresses
• Use clear, consistent branding
• Avoid spammy content
• Send at a stable volume

Important note

Dedicated IPs are most useful when you have steady, significant sending volume. If your volume is low, shared IPs may actually perform better because the provider’s shared reputation can help you.

If you want, I can also show you:

• how to set this up in a specific provider like SendGrid, Mailgun, Postmark, AWS SES, or SparkPost
• or a step-by-step warm-up plan for transactional email.