How to Warm Up a New IP Address: A Step-by-Step Guide

You can’t just start sending thousands of emails through a new IP address, whether it’s dedicated or brand new.

Email providers do not trust new IPs. Before they begin putting your messages in the inbox, they must “see” regular sending, few complaints, and positive engagement.

IP warm-up helps you achieve precisely that.

Consider it a polite, slow introduction to the world of mailboxes. Your reputation will improve and your deliverability will increase if you move more slowly.

In this guide, we’ll walk through:

• Why is IP address warm-up important 
• The exact steps to warm up a new or dedicated IP address 
• A week-by-week IP address warm-up schedule 
• Common problems and how to fix them 
• Tools and best practices to stay on the safe side 

Let’s dive in.

 

What is an IP address warm-up? (and why it matters for deliverability)

IP address warm-up is the process of gradually increasing your email sending volume over several days or weeks, allowing mailbox providers like Gmail, Outlook, Yahoo, and corporate servers to establish trust with your IP address.

 

Why is it important?

When an IP address is new or hasn’t been active for a long time, mailbox providers consider it “unknown”.  

Unknown senders get heavy scrutiny. If you suddenly send thousands of emails on day one, your IP address appears to be that of a spammer.

This leads to:

• Spam folder placement 
• Higher bounce rates 
• Blocks from major ISPs 
• Slow reputation growth 
• Lower open rates 
• Long-term deliverability problems 

The whole goal of warming up is to build a positive reputation by showing that:

• You send to real people 
• Your audience engages with your messages 
• You’re not blasting unsolicited contacts 
• Your volume grows at a logical pace 

If mailbox providers see engagement (opens, replies, clicks), your reputation grows faster.

 

How to  warm up a new IP address: Step-by-step 

This is the simplest way to warm up a new IP address effectively.

Step 1: Send to your hottest contacts first

Your most engaged audience – the people who always open and click your emails – should be the first group to receive your warm-up emails.

Remember, you are trying to build trust and reliability with your mailbox providers. This isn’t the time to send emails to cold leads or inactive lists.

 

Step 2: Start extremely small

Don’t send more than 50–100 emails on day one. Mailbox providers want to see slow, healthy growth.

 

Step 3: Increase volume gradually

Your warm-up should grow in small increments, especially during the first 14 days. Only double or increase your volume by a maximum of 50% each subsequent day if your metrics are flawless.

 

Step 4: Monitor your key deliverability metrics

During the warm-up process, keep an eye on:

• Bounce rate 
• Spam complaints 
• Open rates 
• Click rates 
• Unsubscribes 
• Spam placement 

If anything spikes negatively, slow down.

 

Step 5: Avoid cold traffic

Avoid purchasing or renting lists, and don’t cold prospect during the warm-up process. 

 

Step 6: Maintain consistent sending days

Mailbox providers like predictability. Send daily (Monday–Friday) during your warm-up process.

 

Step 7: Authenticate your domain

Before you start warming up:

• Set up SPF, 
• Enable DKIM, 
• Add DMARC, 
• Verify your sending domain 

This boosts trust instantly and speeds up warm-up success.

 

Recommended IP address warm-up schedule you can follow week by week

This schedule works for most senders, especially businesses warming up a dedicated IP address.

Feel free to adjust based on engagement and list size.

Week 1 (Days 1–7): Slow and steady

Focus: Only send to highly engaged subscribers.

Day	Emails to Send
1	50–100
2	100–200
3	200–350
4	350–500
5	500–700
6	700–1,000
7	Rest or repeat Day 6

 

Week 2 (Days 8–14): Moderate growth

Add your “warm but less active” subscribers.

Day	Emails to Send
8	1,000–1,500
9	1,500–2,000
10	2,000–3,000
11	3,000–4,000
12	4,000–5,000
13	5,000–6,000
14	Repeat or rest

 

Weeks 3–4: Scale to full volume

At this stage, you can include more segments or full lists as long as performance remains healthy.

Grow by 20%–40% per day.

If you’re a SaaS, fintech, e-commerce, or newsletter brand sending 50k–300k+ monthly emails, it may take 4–6 weeks to fully ramp up.

Important rule:

If complaints or bounces go up, pause growth for 24–48 hours.

 

Common IP address warm-up problems and how to fix them fast

Warming up a new IP address doesn’t always go smoothly, but most issues have simple fixes.

1. Emails landing in spam during warm-up

Possible causes are:

• Sending too much volume of emails too fast 
• Low engagement 
• Poor domain reputation 
• Bad list quality 

Fix:

• Reduce your sending volume for 2–3 days 
• Send only to your most engaged subscribers 
• Improve domain authentication 

2. High bounce rates

This usually means the list is not clean. It contains some invalid email addresses.

Fix:

• Validate your email list before continuing 
• Stop sending to low-quality lists 
• Remove inactive or unengaged contacts 

3. Suddenly poor open rates

This is often a sign of spam placement.

Fix:

• Slow down your warm-up. 
• Re-segment 
• Improve subject lines 
• Remove cold or inactive subscribers 
• Check if Gmail or Outlook is blocking you 

4. Low engagement from day one

Your warm-up list may not be your true “hot list”.

Fix:
Send to:

• Customers 
• Buyers 
• Subscribers who opened or clicked in the last 30–90 days 

You need that positive engagement boost to grow your reputation.

5. Mailbox provider throttling

Some mailbox providers will delay or limit the number of emails you can send.

Fix:
This is normal; just reduce your daily growth.

 

Tools and Best Practices for Keeping a Healthy IP Reputation

A strong warm-up requires the right tools and ongoing best practices.

Best IP warm-up tools

These are tools that help automate sending patterns, monitor inbox placement, and protect reputation. They are:

• Go-Mailer warmup system 
• Mailflow warmup 
• Mailreach 
• Warmup Inbox 
• Instantly (for outreach warmup) 
• GlockApps (for inbox monitoring) 
• Mail-Tester (for spam score checks) 

Choose based on your stack and whether you’re doing marketing, transactional, or cold emails.

 

Best practices to maintain a healthy IP address reputation

1. Keep your lists clean

Regularly remove:

• Hard bounces 
• Spam complainers 
• Unengaged subscribers 
• Role-based emails (info@, admin@, etc.) 

2. Avoid sudden sending spikes

If you plan to send a big campaign, ramp up to it gradually.

 

3. Send relevant, valuable content

Mailbox providers track engagement heavily. They check if people are opening, clicking, and responding to your emails.

 

4. Authenticate everything

Authenticate SPF, DKIM, DMARC, BIMI (optional).

 

5. Use consistent sending patterns

Random bursts look suspicious; rather be consistent with sending emails.

 

6. Don’t switch IPs frequently

Stay consistent once your warm-up is complete.

 

Finally…

Warming up a new IP address is one of those tasks that looks boring on the surface, but it’s the difference between a campaign that thrives and one that dies in the spam folder.

If you:

• start small, 
• send to your hottest contacts, 
• grow gradually, and 
• monitor performance closely… 

Your IP address reputation will strengthen, and your deliverability will improve dramatically.

A warm IP equals a healthy sender reputation, and a healthy reputation equals more opens, more clicks, and more revenue.