Warming up your email account helps improve deliverability before starting cold outreach. If your account is new or inactive, email providers are more likely to flag your messages as spam.
This guide shows how to warm up your account using Hunter’s Inbox Protection or by manually increasing sending volume.
Why email warm-up matters
Without a sending history, your email account has no reputation. This can lead to:
Emails landing in spam
Messages being blocked or delayed
Lower open and reply rates
Warming up gradually builds trust with email providers by showing consistent, legitimate activity.
Warm up with Inbox Protection (Paid feature)
Inbox Protection is Hunter’s built-in warm-up solution. It automates the entire process and reduces manual effort.
Here’s what it does:
Sends emails from your account to a network of real inboxes
Generates natural replies and engagement
Gradually increases sending volume over ~30 days
Switches to maintenance mode to preserve your reputation
This approach builds a strong sender reputation through realistic email activity.
👉 For setup steps and details, see Inbox Protection: warm up and protect your sender reputation
Warm up manually
If you prefer you can manually increase your sending volume over time, or use our progressive sending feature for email accounts that haven’t been active recently.
💡Progressive sending is only available for newly connected inboxes or inboxes that haven’t sent emails via Hunter in the last 30 days—if your inbox is already actively sending, you won’t see this option.
Step 1: Open the Email accounts center
Go to the Email accounts center
Find the account you want to warm up
Click View
Step 2: Adjust the daily sending limit
Open the Profile tab
Update the Daily sending limit or enable Progressive sending
Click Save profile
👉 More on Progressive sending here
Best practices for manual warm-up
Start low, scale slowly
Begin with 10–20 emails/day and increase by 5–10 every few days.Keep a consistent schedule
Send emails daily. Avoid sudden spikes or long pauses.Prioritize engagement
Aim for opens and replies—these build sender trust.Mix email types
Include real conversations (replies, internal emails), not just cold outreach.Focus on quality
Personalize emails and target relevant contacts.Verify emails before sending
Verify your emails to reduce bounces.Avoid risky patterns
No large batches, misleading subject lines, or too many links early on.Monitor performance
Track opens, replies, and bounces. Pause increases if metrics drop.Be patient
Warm-up typically takes 2–4 weeks.
👉 For a detailed guide on how to manually warm up your email account, you can visit our Cold Email Guide here.
What to expect
With Inbox Protection
During the 30-day warm-up phase:
Hunter automatically sends warm-up emails from your account and generates real replies, progressively increasing volume from a few emails per day up to approximately 30–40 emails per day
Your warm-up status, daily interactions, open rate and reply rate, are all visible in the Inbox Protection tab of your email account profile
Your account is locked from sending in Sequences during this period to ensure warm-up is the primary activity — sending is automatically unlocked once warm-up completes and the account moves to Protection active status
After warm-up completes, Inbox Protection switches to maintenance mode and continues running in the background to protect your reputation over time.
With manual warm-up
During a manual warm-up:
Sending limits increase gradually as you raise them over time
Deliverability improves progressively as positive engagement builds trust with inbox providers
Spam placement decreases as your domain establishes a sending history
A typical manual warm-up period lasts 2–4 weeks, depending on your starting volume, the quality of your recipient list, and how consistently you send during the ramp-up period.
💡 Tip: Whichever method you use, avoid sudden spikes in sending volume and make sure your recipient list is verified before you start. Bounces during warm-up can slow down or undo your progress
Common questions or issues
How long should I warm up an account?
At least 2–4 weeks before sending high-volume sequences.
Can I skip warm-up?
Not recommended. Skipping warm-up increases the risk of spam filtering or account issues.
What if my emails still go to spam?
Pause increases and review your sending behaviour, email content, and engagement levels.
Email deliverability is a significant concern when you are doing cold email outreach! If you have any questions, feel free to reach out to us via chat or email anytime at contact@hunter.io.