Smartlead Email Warmup: How to Warm Up Your Email Accounts

Smartlead email warmup is a free, unlimited feature on every plan that sends and replies to emails between a connected mailbox and Smartlead’s warmup pool to build sender reputation. It is switched on per mailbox in the Warm-up tab, where the key settings are daily volume, Daily Ramp-Up, randomized numbers and a reply rate of 20-30%. Plan at least two weeks before campaigns.

Last updated: October 2026. Prices checked against Smartlead’s official pricing page.

What is Smartlead email warmup?

Smartlead email warmup is an automated process that exchanges emails between a new mailbox and other mailboxes in Smartlead’s pool, opening and replying at a set rate so inbox providers see normal, wanted traffic. The goal is a sending reputation strong enough that cold campaigns land in the inbox instead of spam.

“unsolicited messages sent in bulk via email”

Source: Wikipedia, Email spam

Inbox providers judge a new mailbox by its history, and a mailbox with no history that suddenly sends bulk email looks like the definition above. The general concept is covered in what email warmup is and whether it is needed; this guide focuses on Smartlead’s settings. There are five things the warmup engine does for each mailbox:

• Pool exchange: Sends emails to and receives emails from other mailboxes in Smartlead’s warmup network, whose addresses are validated every six hours.
• Reply simulation: Replies to a share of received warmup emails at the configured reply rate, which Smartlead recommends keeping between 20% and 30%.
• Volume randomization: Varies the daily count between chosen thresholds so the sending pattern resembles a person rather than a script.
• Daily ramp-up: Gradually raises daily warmup volume for fresh domains until it reaches the configured maximum, as a one-time process.
• Identifier tagging: Places a unique two-word phrase in each warmup email so mail filters can label or archive warmup traffic.

In short, warmup gives a new mailbox the sending history it needs before it carries real outreach.

Is warmup included on every Smartlead plan?

Warmup is included on every Smartlead plan with no extra charge and no cap on the number of mailboxes. Smartlead’s pricing FAQ answers the question directly, and the only difference between plans is the warmup pool tier: Foundation on Base, Growth on Pro and Premium on the two Unlimited plans.

Source: Smartlead pricing page (smartlead.ai/pricing) and help center article 438 (warmup pool), checked October 2026.

Every plan gets unlimited warmup, and higher plans get a stronger pool rather than more warmup.

The $59 per month add-on shown near the warmup row on Base and Pro buys verified prospect emails from SmartProspect, not warmup. The Smartlead pricing breakdown explains that add-on in detail. Warmup itself never costs extra.

How to turn on warmup for a mailbox

Turning on warmup is a three-click change made per mailbox from the Email Accounts tab, and statistics start appearing within minutes. The mailbox must already be connected through Google OAuth, Outlook or SMTP, so connect it first using the guide to connect Gmail and Google Workspace to Smartlead.

1. Open the Email Accounts tab and click the mailbox to warm up.
2. Open the Warm-up tab and choose the configuration (daily volume, ramp-up, randomization and reply rate).
3. Toggle Enable Warmup and click Save. Warmup statistics appear within a few minutes.

If the domain is new, switch on Daily Ramp-Up in the same session, because Smartlead says enabling it later does not work as intended. Enable both together on day one.

Which warmup settings should you choose?

The recommended Smartlead warmup settings are a modest daily volume, Daily Ramp-Up for fresh domains, randomized numbers and a reply rate between 20% and 30%. These values come from Smartlead’s help article on enabling warmup and change once a mailbox starts sending live campaigns.

Source: Smartlead help center articles 52, 63 and 275, checked October 2026.

The table reduces to one rule: keep total traffic per mailbox modest and let ramp-up and randomization make it look human.

“A healthy 20-30% reply rate has proven to boost deliverability and reputation significantly.”

Source: Smartlead help center, How to enable AI email account warm-ups (helpcenter.smartlead.ai/en/articles/52-how-to-enable-ai-email-account-warm-ups)

A reply rate above 30% is not recommended unless the sender knows the trade-offs. Stay inside the 20-30% band.

How does Daily Ramp-Up work?

Daily Ramp-Up is a Smartlead warmup option that starts a fresh mailbox at a low daily volume and raises it gradually until it reaches the configured maximum. It is a one-time process meant for new domains, and Smartlead recommends enabling it at the same time as warmup itself.

Smartlead’s API documentation shows an example ramp from 5 emails on day 1 to 30 on day 10, split between 15 warmup and 15 campaign emails, and 50 by day 20. Progress is visible in the mailbox’s Overview tab as a seven-day summary. Mailboxes that are already warm, or that move from another warmup tool, do not need ramp-up.

Ramp-up is for new domains only, and it must start on the same day as warmup.

How long should you warm up before sending?

Smartlead recommends warming a new inbox for at least two weeks before sending campaigns or running A/B tests. Its API documentation adds that a warmed SMTP mailbox can handle 50-100 emails a day after 30 days of warmup, so two weeks is the floor and a month gives more headroom.

Warmup does not stop when campaigns begin. It keeps running in the background, and Smartlead’s auto-adjust option reduces it as campaign volume grows. A practical plan is to connect and warm mailboxes on day one, build the lead list and sequence during the warmup weeks, then launch with a low daily limit. The complete Smartlead setup guide shows where warmup fits in the full launch order.

Two weeks is the minimum, and the mailbox should keep warming for as long as it sends.

Warmup during live campaigns: auto-adjust and limits

Warmup during a live campaign runs alongside outbound sending, and Smartlead manages the balance through the Auto-Adjust Warmup/Sending Ratio setting in each mailbox’s Warm-up tab. When campaigns are active, the AI lowers the warmup count so the mailbox’s combined daily traffic stays within a safe range.

Smartlead’s help articles describe five rules for running warmup and campaigns together:

• Auto-Adjust ratio: Lowers the daily warmup count by about 7-10 emails while campaigns run, and roughly 10 warmup emails a day are still sent regardless.
• Separate counters: Warmup emails never count toward the plan’s monthly send allowance or toward a mailbox’s campaign daily limit.
• Combined ceiling: Campaign plus warmup traffic kept at about 50 emails per mailbox per day in total, the level Smartlead’s quota article recommends.
• Lower warmup volume: Total daily warmup set to 10-20 while a campaign is active, then raised again once that campaign has finished.
• Weekday-only option: The Send Warm-up Emails Only on Weekdays setting, which limits warmup to Monday through Friday to match business hours.

Campaign pacing itself is set in the sequence and settings tabs, covered in the Smartlead email sequence guide. Keep warmup on, just quieter, while campaigns run.

How do you filter warmup emails out of the inbox?

Warmup emails are filtered using the custom warm-up identifier, a unique two-word phrase that Smartlead assigns to each mailbox and inserts into every warmup email body. The phrase is shown in the mailbox’s Warm-up tab and can be used in a Gmail or Outlook filter to mark, label or move warmup traffic.

1. Copy the two-word Custom warm-up identifier from the mailbox’s Warm-up tab.
2. Create a mail filter that matches emails containing that phrase.
3. Set the filter to mark as read, apply a label or move to a folder.
4. Never set the filter to delete; deleting warmup emails undermines the warmup signals.

Smartlead is explicit that warmup emails should be filtered, never deleted. A label keeps the inbox clean while the warmup keeps working.

How do warmup pool tiers and Ultra Premium work?

A warmup pool tier is the quality level of the mailbox network a Smartlead account warms up with. Base accounts use the Foundation pool, Pro uses Growth, and Unlimited Smart and Prime use Premium. Unlimited Smart and Prime mailboxes can also qualify for Ultra Premium, which Smartlead says is free for qualified users for now.

The current pool appears in a banner on the Email Accounts page, with a pool score out of 100 and a See how to upgrade link. Smartlead’s help center lists six factors that decide Ultra Premium eligibility:

• Account age: How long the account and its mailboxes have been active, since older, consistent senders earn more trust from the pool.
• Authentication hygiene: Correct SPF, DKIM and DMARC records on every sending domain connected to the account.
• Bounce rate: The share of sent emails that bounce, which should stay low through verified lists and bounce protection.
• Sending volume: Steady daily volume within recommended per-mailbox limits rather than sudden spikes from a few inboxes.
• Reply rate: Engagement with campaign and warmup emails, which signals that recipients want the traffic.
• ESP diversity: A mix of email service providers across connected mailboxes rather than a single provider.

Smartlead states Ultra Premium will become a paid add-on later, so treat free access as temporary. Better hygiene raises the pool score on any plan.

What happens when a mailbox bounces in the warmup pool?

A mailbox that bounces warmup emails is moved into a cool-off period, which protects the rest of Smartlead’s pool from a failing sender. The mailbox is retested after four hours, and if it is still rejecting mail it is removed from the warmup network until the owner fixes the issue and contacts support.

Smartlead validates pool addresses every six hours with a quick check followed by a six-step SMTP verification, and its help center put the pool at 25 million warmup emails a day as of February 2024. A disabled warmup usually points to a mailbox problem such as a disconnected account, a full inbox or a blocked domain, not to the pool.

Fix the mailbox first, then ask support to reinstate warmup with proof of the fix.

Monitoring warmup health

Monitoring warmup means checking each mailbox’s warmup statistics, ramp-up progress and pool standing on a regular schedule rather than only when replies drop. Smartlead surfaces these numbers in several places, and its AI tools can run the same checks on request.

There are five places to watch warmup health in Smartlead:

• Warmup statistics: Daily warmup numbers on the mailbox page, which start appearing a few minutes after warmup is switched on.
• Overview tab summary: A seven-day summary per mailbox that shows whether Daily Ramp-Up is progressing toward its configured maximum.
• Pool score banner: The Email Accounts banner showing the current pool tier and a score out of 100 with upgrade guidance.
• SmartAssistant diagnostics: The built-in AI assistant, included on all plans, which can run spam, warmup and DNS checks on request.
• SmartDelivery tests: A paid add-on from $49 per month that runs inbox placement tests with a seed list across providers.

A weekly check of these five catches most warmup problems early. If placement drops despite healthy warmup, see why Smartlead emails go to spam.

Common Smartlead warmup mistakes

Most Smartlead warmup problems come from changing settings at the wrong time or pushing volume too early. The fixes are simple once the cause is known, and Smartlead’s help center documents each one across its warmup and deliverability articles.

There are five mistakes worth avoiding:

• Late ramp-up: Enabling Daily Ramp-Up days after warmup has started, which Smartlead says will not work as intended for that mailbox.
• Deleting warmup emails: Filters that delete warmup traffic, which removes the signals the pool depends on; labeling or archiving works instead.
• Excessive reply rate: A reply rate above 30%, which Smartlead advises against unless the sender is an experienced deliverability specialist.
• Early launch: Sending campaigns before the recommended two weeks of warmup, which leaves the mailbox without enough sending history.
• Switching warmup off: Turning warmup off once campaigns start, instead of letting Auto-Adjust lower it while it keeps running.

Avoiding these five keeps warmup doing its job quietly in the background.

Bottom line: how should you run Smartlead warmup?

Smartlead email warmup works best when it starts on day one with Daily Ramp-Up, a 20-30% reply rate and randomized volume, runs for at least two weeks before campaigns, and stays on at a lower volume afterwards. It is unlimited and included on every plan, so there is no cost reason to skip it.

“Warmup is the cheapest deliverability insurance Smartlead offers, because it is free.”

Source: GrowthStackKit, Smartlead Review

For the full view of Smartlead’s strengths and limits, read the Smartlead review. To test warmup without paying, the Smartlead free trial guide explains what the 14 days include.

Frequently asked questions

The 12 most-asked questions about Smartlead email warmup.

Is Smartlead email warmup free?

Yes. Warmup is unlimited and included on every Smartlead plan, from Base at $39 per month to Unlimited Prime, and it is also available during the 14-day free trial. Plans differ only in warmup pool tier, not in warmup volume or price.

How long should I warm up a mailbox in Smartlead?

Smartlead recommends warming a new inbox for at least two weeks before sending campaigns or A/B tests. Its API documentation notes a warmed SMTP mailbox can handle 50-100 emails a day after 30 days of warmup, so longer warmup gives more room.

What reply rate should I set for Smartlead warmup?

Smartlead recommends a reply rate between 20% and 30%. Its help center says a reply rate above 30% is not recommended unless the sender is an expert who understands the trade-offs. The setting lives in each mailbox’s Warm-up tab, next to daily volume, Daily Ramp-Up and randomized warmup numbers.

Should I enable Daily Ramp-Up in Smartlead?

Enable Daily Ramp-Up for fresh domains and turn it on at the same time as warmup, because Smartlead says enabling it later will not work as intended. Mailboxes that are already warmed, or that come from another warmup tool, do not need it.

Do Smartlead warmup emails count toward my sending limit?

No. Warmup emails do not count toward the plan’s monthly email sends or toward a mailbox’s campaign daily limit. Smartlead still recommends keeping campaign plus warmup traffic at about 50 emails per mailbox per day in total. Warmup also does not use the free trial’s 2,500 sends.

Should I keep warmup on while a campaign is running?

Yes. Warmup should keep running during campaigns at a lower volume. Smartlead suggests 10-20 daily warmup emails while a campaign is active, and the Auto-Adjust Warmup/Sending Ratio setting lowers warmup automatically as campaign sending grows. Turning warmup off once campaigns start is a common mistake.

How do I stop warmup emails cluttering my inbox?

Copy the two-word custom warm-up identifier from the mailbox’s Warm-up tab and build a mail filter on it that marks warmup emails as read, labels them or moves them to a folder. Never delete warmup emails, because that weakens the warmup signals.

What is the difference between Foundation, Growth and Premium warmup pools?

They are pool quality tiers tied to the plan. Base uses Foundation, Pro uses Growth, and Unlimited Smart and Unlimited Prime use Premium. Unlimited Smart and Prime mailboxes can also qualify for the Ultra Premium pool based on account health.

How do I qualify for Smartlead’s Ultra Premium warmup pool?

Eligibility depends on account age, SPF, DKIM and DMARC hygiene, bounce rate, sending volume, reply rate and ESP diversity. The Email Accounts banner shows the current pool and a score out of 100. Smartlead says Ultra Premium is free for qualified users for now.

Why was warmup disabled on my Smartlead mailbox?

A mailbox that bounces in the warmup pool goes into a cool-off period and is retested after four hours. If it still rejects mail, it is removed from the warmup network until the issue is fixed and support is contacted with proof.

Does the $59 add-on on Base and Pro pay for warmup?

No. The $59 per month add-on on Base and Pro buys verified prospect emails from SmartProspect. Warmup is unlimited and included on every plan at no extra cost, and only the pool tier changes between plans. On Unlimited Smart and Prime, verified prospect emails are included at no extra cost.

Can Smartlead warm up only on weekdays?

Yes. The Send Warm-up Emails Only on Weekdays option limits warmup activity to Monday through Friday, which matches how most business mailboxes send email during a normal work week. The option sits in the mailbox’s Warm-up settings and can be combined with Daily Ramp-Up, randomized volume and the recommended 20-30% reply rate.