What is Email Warm up ?

Email warmup is the process of gradually increasing the volume of emails sent from a new email address or domain to establish a good sender reputation with ISPs (such as Gmail, Outlook, etc.) and avoid being flagged as spam. Without proper warm-up, large-scale campaigns risk getting marked as spam or blocked entirely.

Why Warm Up Is Important:

• No Reputation Yet: New IPs/domains have a neutral or even negative “trust score.”

• Spam-filter Sensitivity: Sudden spikes in outbound volume trigger alarms. ISPs might block or filter them.

• Deliverability: A good sending reputation means your emails land in the inbox, not the junk folder. Warming up helps establish you as a trustworthy sender.

Email Warmup Can Be:

• Manual — Sending a few personal emails each day yourself.

• Automated — Using tools like E-Warmup.com or Seedlist.ai, etc.

Manual vs. Automated Warmup:

• Manual

  • You personally send a small number of emails to testers or colleagues.

  • Pros: Full control; tailor content.

  • Cons: Time-consuming; hard to scale.

• Automated Tools (e.g., E-Warmup, Seedlist.ai)

  • These platforms auto-exchange emails among a network to simulate engagement.

  • Pros: AI-based, Automated, Hands-off, consistent.

  • Cons: Added cost.

Now let's talk about the benefits of an automatic email warm-up tool:

• You don't have to do anything; everything is automated

• Unique delivery control algorithms

• Efficient warm-up thanks to a huge network of highly reputable email addresses

• Automatic warm-up temperature increase communication of emails in a thread on the selected Topic

• Communication of emails in a thread on the selected Language

• Statistics and tests to track progress

• Increase and maintain deliverability even during email campaigns with fast and high-quality support

Each provider has its own algorithms and parameters that determine it. For example:

• Mailbox & Domain age.

• Are SPF, DKIM, and DMARC parameters Pass or Fail?

• Number of spam complaints;

• The presence of an email address in the blacklists.

• Number of attempts to send an email to non-existent addresses (bounced emails);

• Spam traps;

• Regularity of activity;

• Content in outgoing emails;

• Open rate;

• Response rate;

And these are only the expected parameters that may differ and change for different providers.

It's worth mentioning that brand-new emails have a low reputation by default, which will prevent you from sending the 2,000 emails promised by G Suite from day one. The provider needs time to monitor your activity.

Warming up process

Today, it's not enough to just send out a daily rate of emails. To show email providers that you are an honest and legitimate sender, it is worth emulating the activity of a real user, namely:

• Sending and daily increase of email limit

• A large list of email addresses for interaction

• Receiving emails

• Reading emails

• Mark as important

• Replies to emails

• Removing emails from SPAM

• Using snippets (personalization of emails)

By following all the above points, you will minimize the chances that your emails will end up in the SPAM folder and teach providers such as Google, Outlook, Yahoo, Zoho, and many others that your emails should be placed in the "Inbox".

Here are the key benefits of email warm-up:

1. Improved Deliverability

Warming up builds trust with email providers (like Gmail, Outlook, Yahoo), increasing the chances your emails land in the inbox, not the spam folder.

2. Builds Sender Reputation

Gradual, consistent sending with good engagement signals (opens, replies, low bounces) helps you earn a positive reputation tied to your domain and IP.

3. Reduces Spam Flags & Blocks

Jumping straight into high-volume sends without warm-up can trigger spam filters or get your IP/domain blacklisted. Warm-up helps you avoid that risk.

4. Ensures Better Engagement Rates

Starting with smaller, targeted, and engaged audiences improves your open and click-through rates, which ISPs love to see.

5. Prevents IP Blacklisting

Reputation-damaging events (like mass bounces or complaints) during cold sending can land your IP on blacklists. Warm-up keeps your sender score clean.

6. Allows Safe Scaling

Want to send 500 or 5,000 emails a day? Warm-up gives your infrastructure time to ramp up safely, avoiding sudden delivery issues.

7. Supports Long-Term Campaign Success

Consistent deliverability leads to better reach, stronger customer trust, and more effective marketing over time.

Having explored both manual and automated options for email warm-up and deliverability, we hope this information helps you choose the approach that best suits your needs.