Warmerly
5 ($19), 25 on Growth ($49)
Warmerly
Smartlead
One-to-one · Mailboxes on the starting plan
Mailboxes on the starting plan
One row, in depth: what each tool does, the verified numbers, and who each suits.
Smartlead details read from its pricing page, home page and help centre on 17 and 19 October 2026.
Warmerly
5 ($19), 25 on Growth ($49)
Smartlead
Unlimited
The short answer
Mailboxes on the starting plan, in one look.
Warmerly Starter connects 5 mailboxes, and more means a higher plan (Growth 25, Agency 100). Smartlead says every plan includes unlimited email accounts, including its $39 Base plan, and it limits emails and contacts instead. Its fair use policy says fair and reasonable use applies on unlimited plans. Last checked 19 October 2026.
SmartleadSmartlead ahead on this row
Unlimited
The picture
Drawn side by side.
The cheapest plan that connects your mailboxes
Monthly price against the number of mailboxes you connect. Warmerly steps up at 5, 25 and 100. Smartlead Base stays flat.
WarmerlySmartlead
Warmerly
$19Starter
Up to 5 mailboxes on this plan.
Smartlead
$39Base
Unlimited mailboxes. 6,000 emails a month shared between them.
The numbers behind this chart
| Plan | Mailboxes it connects | Price |
|---|---|---|
| Warmerly Free | 1 mailbox | $0 a month |
| Warmerly Starter | 2 to 5 mailboxes | $19 a month |
| Warmerly Growth | 6 to 25 mailboxes | $49 a month |
| Warmerly Agency | 26 to 100 mailboxes | $179 a month |
| Warmerly Max | More than 100 mailboxes | Priced on a call |
| Smartlead Base | Any number of mailboxes | $39 a month, 6,000 emails a month |
| Smartlead Pro | Any number of mailboxes | $94 a month, 90,000 emails a month |
| Smartlead Unlimited Smart | Any number of mailboxes | $174 a month, 150,000 emails a month |
| Smartlead Unlimited Prime | Any number of mailboxes | $379 a month, 500,000 emails a month |
Mailboxes are drawn on a log axis so the 1, 5, 25 and 100 steps are visible. Smartlead's pricing FAQ says all plans include unlimited email accounts at no extra cost. Warmerly's Free plan has a cap of 100 sends a month; Starter's 5 mailboxes top out near 4,500 a month and Growth's 25 near 22,500 (30 a day over 30 days, our arithmetic).
What the email allowance leaves each mailbox
Average emails a day per mailbox if a plan's monthly allowance is shared evenly. Warmerly's 30 a day is a ceiling, not a quota.
WarmerlySmartlead
Warmerly
30a day, up to
Default limit per mailbox. The ramp and bounce brake can lower it.
Smartlead, shared evenly
- Base, 6,00040
- Pro, 90,000600
- Unlimited Smart, 150,0001,000
- Unlimited Prime, 500,0003,333
The numbers behind this chart
| Fleet size | Warmerly default limit | Smartlead Base, 6,000 | Pro, 90,000 | Unlimited Smart, 150,000 |
|---|---|---|---|---|
| 5 mailboxes | Up to 30 | 40 | 600 | 1,000 |
| 20 mailboxes | Up to 30 | 10 | 150 | 250 |
| 60 mailboxes | Up to 30 | 3.3 | 50 | 83.3 |
| 100 mailboxes | Up to 30 | 2 | 30 | 50 |
Warmerly's 30 a day is each mailbox's default daily campaign limit; the ramp and a bounce-rate brake can only lower it. At 30 a day over 30 days, 5 mailboxes top out near 4,500 sends a month, 25 near 22,500 and 100 near 90,000.
On screen
What it looks like.
WarmerlySample data
How Warmerly does it
Warmerly, in detail.
Mailbox count is the main thing Warmerly sells on: 1 on Free, 5 on Starter, 25 on Growth, 100 on Agency.
01
The numbers by plan
Free allows 1 mailbox, Starter 5, Growth 25 and Agency 100. There is no 'unlimited' tier in the code, so the top published plan is described as 100. Above that is Max, agreed on a call.
Warmerly product, checked 19 October 2026
02
Where the limit bites
Connecting a mailbox past the limit is refused at the moment you try, with a clear message, so you meet the ceiling when you cross it rather than later on a bill.
Warmerly product, checked 19 October 2026
03
What counts
Connected mailboxes count towards the limit. Hosted mailboxes bought from Warmerly do not use a plan slot and are bought per mailbox instead, $2.99, $1.99 or $0.99 a month on Starter, Growth and Agency.
Warmerly product, checked 19 October 2026
04
Cost per mailbox
Price divided by mailboxes works out at $3.80 on Starter, $1.96 on Growth and $1.79 on Agency (our arithmetic).
Warmerly product, checked 19 October 2026
05
Every mailbox warms
Warmup and campaigns run on every connected mailbox on every plan, including Free. Each mailbox has its own daily campaign limit, 30 by default.
Warmerly product, checked 19 October 2026
06
The daily limit is a ceiling
A mailbox sends at most the lower of its own daily campaign limit (30 by default) and its ramp cap. A rising bounce rate cuts that cap further, so 30 a day is an upper bound, not a promise.
Warmerly product, checked 19 October 2026
07
What a plan's mailboxes can send
At 30 a day over 30 days, 5 mailboxes top out near 4,500 sends a month, 25 near 22,500 and 100 near 90,000 (our arithmetic).
Warmerly product, checked 19 October 2026
08
What counts as a mailbox
The count is connected, sending-enabled mailboxes of the real kind, leaving out ones flagged or dead.
Warmerly product, checked 19 October 2026
How Smartlead does it
Smartlead, in detail.
The pricing FAQ says all plans include unlimited email accounts at no extra cost. Smartlead meters emails sent and contacts instead, and its fair use policy applies on top.
01
Unlimited accounts on every plan
The pricing FAQ answers the mailbox question with: 'All Smartlead plans include unlimited email accounts at no extra cost.' The home page says 'Add unlimited mailboxes and store unlimited leads'.
smartlead.ai/pricing and https://www.smartlead.ai · read 19 October 2026
02
Rotation across mailboxes
The pricing FAQ says Smartlead automatically rotates sending across all connected mailboxes within a campaign.
smartlead.ai/pricing · read 19 October 2026
03
How many people really use
Smartlead's own benchmark page says the median account runs 20 mailboxes, the smallest quarter run 7 or fewer and the largest quarter 60 or more. This describes its customers, not a limit.
smartlead.ai/benchmarks/how-many-mailboxes-for-cold-email · read 19 October 2026
04
Ready-made mailboxes cost extra
Mailboxes bought through SmartSenders are priced per mailbox, from $3.99 to $9 a month depending on the provider, with domains $13 to $19 a year. Connecting your own is covered by the plan.
smartlead.ai/pricing · read 19 October 2026
05
The daily limit is yours to set, and campaigns share it
The help centre says the daily limit of a sender account is split across the campaigns using it, so with a limit of 40 and 4 campaigns you cannot expect 40 in each. The limit resets at 00:00 in the timezone set on your Smartlead account.
helpcenter.smartlead.ai/en/articles/228-my-campaign-is-not-sending-emails-or-sending-less-volume · read 19 October 2026
06
Its guidance on daily caps
The help centre says to keep early-stage daily caps within 40 to 50, counting warmup and outbound together.
helpcenter.smartlead.ai/en/articles/65-understanding-email-account-disconnection-reasons-in-smartlead · read 19 October 2026
07
Emails are the real meter
Base lists 6,000 emails a month for the whole account, however many mailboxes are connected; Pro lists 90,000, Unlimited Smart 150,000 and Unlimited Prime 500,000. Each email sent, follow-ups included, is one credit; when they run out, new emails wait for the monthly reset or an upgrade.
helpcenter.smartlead.ai/en/articles/392-managing-lead-credits-and-email-credits-quota-in-smartlead · read 19 October 2026
08
Its own fleet-size rules of thumb
Its blog says 1,000 emails a day takes 20 to 30 mailboxes, 5,000 a day takes 100 to 150 and 10,000 a day takes 200 plus, and quotes 50 mailboxes from $39 a month flat. The page does not explain how 6,000 emails a month fits 50 mailboxes.
smartlead.ai/blog/unlimited-mailboxes-cold-email · read 19 October 2026
09
What its own customers run
The benchmark page gives a median pace of 14 cold emails a day per mailbox and 50 as the per-mailbox ceiling, and says its guide advises 15 to 25 a day.
smartlead.ai/benchmarks/how-many-mailboxes-for-cold-email · read 19 October 2026
10
Fair use applies on unlimited plans
Its Fair Use Policy says you must make fair and reasonable use even on an unlimited plan, gives the establishment of mailboxes 'in a manner which contravenes, undermines or subverts the reasonable and acceptable use of the Service' as an example of abnormal use, and lists 100, 300 and 800 mailboxes against plan names that do not all match today's (Basic, Popular, Pro).
smartlead.ai/fair-use-policy · read 19 October 2026
What Smartlead does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- A connected-account cap on its plan pages, pricing fact sheet or help articles read: none is stated. Its Fair Use Policy lists 100, 300 and 800 mailboxes against plan names that do not all match today's (Basic, Popular, Pro) without saying how they apply.
- How 'unlimited accounts' squares with the 'pay only for what you send' line on the home page: both appear, and the basis is not explained.
- Whether the free trial limits mailboxes: not stated.
- Whether the 6,000 emails on Base are enough for the fleet sizes its own blog describes: the pages do not reconcile the two.
The numbers
Only what we could verify.
| Measure | Warmerly | Smartlead |
|---|---|---|
| Mailboxes on the starting plan | 5 ($19), 25 on Growth ($49) | Unlimited |
| Mailboxes on the free option | 1 (Free plan, no card) | Not stated for the free trial |
| Next plan up | 25 (Growth, $49) | Unlimited (Pro, $94) |
| Top published plan | 100 (Agency, $179) | Unlimited (Prime, $379) |
| Above that | Max, by call | No limit stated |
| Cost per mailbox on the starting plan | $3.80 ($19 / 5, our arithmetic) | Falls as you add mailboxes; emails are what is capped |
| Median customer fleet | Not published | 20 mailboxes (its benchmark page) |
| Emails a month at 5 mailboxes | About 4,500 (5 mailboxes, 30 a day, 30 days; our arithmetic) | 6,000 for the whole account (Base), or 1,200 each, about 40 a day (our arithmetic) |
| Daily limit per mailbox | 30 by default, set per mailbox, ramp can lower it | Set by you; help centre suggests 40 to 50 early on, warmup and outbound together |
| Typical daily pace | Not published | 14 a day median, 50 ceiling (its benchmark page) |
| Emails per mailbox at a 20 mailbox fleet | Up to 900 a month each (30 a day ceiling, not a promise) | 300 a month each on Base, about 10 a day (6,000 / 20, our arithmetic) |
| Hosted mailboxes | $2.99, $1.99 or $0.99 a month, outside the slot count | SmartSenders $3.99 to $9 a month each |
| What counts toward the limit | Connected, sending-enabled real mailboxes | No mailbox limit stated on its plan pages |
| Average sends a day per mailbox, 5, 20, 60 and 100 mailboxes | Up to 30 each at any size (a ceiling, not a promise) | Base's 6,000 emails shared out: 40, 10, 3.3 and 2 a day each (our arithmetic) |
The plans
Every plan, side by side.
Warmerly
Free$01 mailbox · capped sends · no card
Starter$195 mailboxes · no cap on sends
Growth$4925 mailboxes · no cap on sends
Agency$179100 mailboxes · client workspaces · API
Smartlead
Base$396,000 emails · 2,000 contacts
Pro$9490,000 emails · 30,000 contacts
Unlimited Smart$174150,000 emails
Unlimited Prime$379500,000 emails
Per month, billed monthly. Every Smartlead plan lists unlimited email accounts; prices read on smartlead.ai/pricing on 17 October 2026 and re-checked on 19 October 2026.
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
Smartlead is ahead on mailbox count
Our reading: if you are building a big fleet, an unlimited count at $39 beats a 5 mailbox plan. This is the clearest place Smartlead is stronger.
But sends are capped there
Our reading: with Base, 6,000 emails a month spread across many mailboxes means very few sends per mailbox. Unlimited mailboxes help most if you also pay for the emails to use them.
For small setups the limit may never bite
Our reading: most people starting out have 2 to 5 mailboxes. Starter covers that for $19, and Free covers 1.
Past 100 is a conversation
Our reading: Warmerly Agency stops at 100 mailboxes. If you will be well above that, Smartlead is the simpler fit or you will need a Max call.
Past about 6 mailboxes, Base's email cap sets the pace
Our reading: 6,000 emails shared by 5 mailboxes is about 40 a day each. By 20 mailboxes it is about 10 a day each, and by 100 it is 2. More mailboxes on Base means more spread, not more sending, unless you move up a plan.
Warmerly's limit is a count you can see
Our reading: Warmerly tells you a number of mailboxes (5, 25, 100) and each one sends up to its own daily limit. Smartlead tells you a number of emails. Pick the meter that matches how you plan.
What the other Smartlead plans give each mailbox
Our arithmetic, 30 days a month: Pro's 90,000 emails shared by 5, 20, 60 and 100 mailboxes is 600, 150, 50 and 30 a day each. Unlimited Smart's 150,000 is 1,000, 250, 83.3 and 50 a day each. Any figure above 50 means the email allowance is not what holds a mailbox back, its own daily limit is.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You run up to 5 mailboxes and want the lowest price.
- You want one mailbox free to try warmup and sending first.
- You want a mailbox ceiling you can see before you hit it.
- You want hosted mailboxes at $0.99 to $2.99 a month without using a plan slot.
Smartlead
Smartlead is the better fit if
- You want more than 100 mailboxes on a published price.
- You plan to add mailboxes steadily and do not want to move plans for it.
- You want mailboxes, domains and DNS set up for you from the same vendor.
- You manage a large fleet for clients.
Questions
How many mailboxes does Smartlead allow?
Unlimited on every plan, including Base at $39. It limits emails and contacts instead, and its fair use policy applies on unlimited plans.
How many mailboxes does Warmerly allow?
5 on Starter ($19), 25 on Growth ($49) and 100 on Agency ($179). Free has 1.
What does a mailbox cost on Warmerly Starter?
$3.80, from $19 divided by 5, by our arithmetic.
How big is a typical Smartlead fleet?
Its benchmark page gives a median customer fleet of 20 mailboxes. Warmerly does not publish one.
Sources
- Smartlead pricing
- Smartlead home page
- Smartlead help: lead and email credits
- Smartlead help: do credits reset
- Smartlead benchmark: how many mailboxes
- Smartlead help: pricing plans
- Smartlead help: my campaign is not sending or sending less volume
- Smartlead help: email account disconnection reasons
- Smartlead blog: unlimited mailboxes for cold email
- Smartlead: pricing as a markdown fact sheet
- Smartlead: fair use policy
Smartlead pages were read on 19 October 2026. Plans and wording change, so check the vendor's own page before you decide. Warmerly details come from the product as it runs today.
More features
- All features
- Starting price (per month)
- Most mailboxes on a published price
- Emails per month on the starting plan
- Highest published send volume
- Contacts on the starting plan
- Warmup
- Spam-folder rescue
- SPF, DKIM and DMARC monitoring
- Inbox placement testing
- Built-in campaign sender
- Shared reply inbox
- LinkedIn steps in the same sequence
- Ready-made mailboxes
- Agency and white-label
- Integrations
- API
- Free plan or trial
See it on your own mailbox.
Connect a mailbox. Warmerly runs alongside whatever you send from now, so you can compare before you move anything.
Free plan, no card. Paid plans: 7-day trial, first charge on day 8.