Warmerly
5
Warmerly
One-to-one · Mailboxes on starting plan
Mailboxes on starting plan
One row, in depth: what each tool does, the verified numbers, and who each suits.
Instantly details read from its pricing and help pages on 15 and 17 October 2026.
Warmerly
5
Unlimited
The short answer
Mailboxes on the starting plan, in one look.
Warmerly Starter connects 5 mailboxes; more mailboxes means a higher plan (Growth 25, Agency 100). Instantly says paid plans connect unlimited email accounts, although its Terms of Service cap a workspace at 100 connected accounts and its warmup pool has limits that apply to SMTP accounts. Last checked 19 October 2026.
Unlimited
The picture
Drawn side by side.
On screen
What it looks like.
WarmerlySample data
How Warmerly does it
Warmerly, in detail.
The mailbox count is the main limit 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. These are the plan's mailboxLimit values. There is no 'unlimited' mailbox tier in the code, so the right way to describe the top plan is 100.
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 402 and a message, from the add-account route, the bulk route, both Google and Microsoft sign-in callbacks and the resume route. You meet the ceiling when you cross it, not a month later.
Warmerly product, checked 19 October 2026
03
What counts as a mailbox
Real, connected mailboxes count. Pool mailboxes and OneMail hosted mailboxes do not use a plan slot. Hosted mailboxes are bought per unit instead: $2.99 a month on Starter, $1.99 on Growth, $0.99 on Agency, so what limits them is the bill, not a cap.
Warmerly product, checked 19 October 2026
04
Cost per mailbox
Dividing price by mailboxes gives $3.80 a mailbox on Starter ($19 / 5), $1.96 on Growth ($49 / 25) and $1.79 on Agency ($179 / 100). The code notes Agency was set to 100 mailboxes so the price per mailbox keeps falling as the plan grows.
Warmerly product, checked 19 October 2026
05
If you go over after a downgrade or plan change
A nightly check compares each workspace to its plan. A workspace that drifts over a limit gets 30 days of grace before it is locked, and a plan change that shrinks the limit applies with no grace (PLAN_CHANGE_GRACE_DAYS = 0).
Warmerly product, checked 19 October 2026
06
Every mailbox warms
Warmup runs on each connected mailbox on every plan, including Free. The limit is how many mailboxes you connect, not how many emails the warmup exchanges. Campaign sending is a separate daily cap per mailbox (30 by default).
Warmerly product, checked 19 October 2026
How Instantly does it
Instantly, in detail.
Instantly's pricing page and help centre say paid plans connect unlimited email accounts. Its Terms and its warmup-pool rules add limits that the pricing page does not mention.
01
Unlimited on paid plans, 2 on the trial
Every paid Outreach plan lists Unlimited Email Accounts, and the pricing FAQ answers 'Can I really connect and warm up unlimited accounts with one subscription?' with 'Yes! You can connect and warm as many accounts as you need from any provider.' The free trial connects at most 2 accounts.
instantly.ai/pricing ; https://help.instantly.ai/en/articles/11991261-getting-started-with-email-accounts · read 19 October 2026
02
Terms of Service: 100 connected accounts per workspace
Section 2.2 of the Terms (last updated 22 September 2026) says Instantly 'currently offers a maximum of one hundred (100) Connected Accounts per workspace' and that the subscriber agrees not to exceed it. That sits beside the 'unlimited' wording on the pricing page. Hypergrowth and Light Speed plans can add workspaces, per the plans comparison table.
instantly.ai/terms (section 2.2); https://help.instantly.ai/en/articles/7920548-email-outreach-plans-comparison · read 19 October 2026
03
Warmup pool limit for SMTP accounts
Accounts connect without limit, but the number of SMTP accounts in the Standard Warmup Pool is capped by plan: 100 on Growth, 500 on Hypergrowth, 1,000 on Light Speed, plus 500 per add-on, subject to a Fair Usage Policy. Going over moves every account in the workspace, including Google and Outlook ones, to the Basic Warmup Pool, which the help article describes as lower engagement and weaker deliverability.
help.instantly.ai/en/articles/11118071-standard-basic-warmup-pool · read 19 October 2026
04
Sending per account
Instantly recommends 30 campaign emails per account per day for most mailboxes, and up to 20 per day for Instantly's own AirMail mailboxes. Warmup emails do not count towards that limit.
help.instantly.ai/en/articles/6248612-account-and-campaign-limits · read 19 October 2026
05
Buying accounts from Instantly
If you do not have mailboxes, Instantly sells them: pre-warmed Google accounts at $10 a month each, done-for-you Google accounts at $5, AirMail accounts at $4, and domains at $15 a year.
help.instantly.ai/en/articles/10273259-instantly-plans-overview · read 19 October 2026
What Instantly does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- Searched instantly.ai/pricing, the plans overview, plans comparison, email accounts dashboard and warmup-pool help articles for a stated cap on Google or Microsoft accounts per plan; only the 100-account limit in the Terms and the SMTP pool limits were found.
- Searched the Instantly Terms and Technical Parameters Addendum for the Fair Usage Policy figures behind the warmup pool limits; the numbers above are the only ones stated.
The numbers
Only what we could verify.
| Measure | Warmerly | |
|---|---|---|
| Mailboxes on starting plan | 5 | Unlimited |
| Mailboxes on the starting plan | 5 (Starter) | Unlimited on Growth, per pricing page |
| Mailboxes on the free option | 1 (Free plan) | 2 (14-day free trial) |
| Mailboxes on the middle plan | 25 (Growth) | Unlimited (Hypergrowth) |
| Stated ceiling in legal terms | 100 on Agency, the top paid plan | 100 connected accounts per workspace (Terms 2.2) |
| SMTP accounts in the standard warmup pool, starting plan | Not applicable: no pool tier by plan found in the code read | 100 (Growth) |
| Price per mailbox, starting plan | $3.80 (our arithmetic: $19 / 5) | Not defined, since accounts are unlimited |
The plans
Every plan, side by side.
Warmerly
Free$01 mailbox · capped sends
Starter$195 mailboxes · no cap on sends
Growth$4925 mailboxes · no cap on sends
Agency$179100 mailboxes · no cap · API
MaxCustomMore than 100 mailboxes
Instantly
Growth$475,000 emails · 1,000 contacts
Hypergrowth$97125,000 emails · 25,000 contacts
Light Speed$358500,000 emails · 100,000 contacts
EnterpriseCustom500,000+ emails · 100,000+ contacts
Per month, billed monthly. Instantly plans all include unlimited email accounts and warmup; prices checked on instantly.ai/pricing on 17 October 2026.
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
Five is plenty for a first campaign, tight for a growing one
Our reading: five mailboxes at the default 30 campaign emails a day is 150 a day, which suits one founder or a small team. An agency running several client domains reaches the Starter limit fast and moves to Growth at $49.
'Unlimited' has a practical edge on Instantly
Our reading: if most of your accounts are Google or Microsoft you are unlikely to meet the SMTP pool limit, but the 100-account Terms limit and the pool rules are worth reading before you plan for hundreds of mailboxes.
A hard mailbox limit is a predictable one
Our reading: Warmerly tells you at connect time when you are at the limit and never meters your sends, so your bill and your mailbox count are the only two things to watch.
Cost per mailbox falls with each tier
Our reading: $3.80, $1.96 and $1.79 per mailbox across Starter, Growth and Agency means the cheapest way to run many mailboxes on Warmerly is the larger plans, not several Starters.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You run up to 5, 25 or 100 mailboxes and want a price that scales with that count
- You want a clear, enforced limit that is shown to you when you connect
- You want hosted mailboxes billed per unit, outside the plan's mailbox count
- You want warmup on every connected mailbox without a separate pool tier
Instantly is the better fit if
- You want to connect many mailboxes on the cheapest paid plan and have no plan to pass 100 in one workspace
- You want to buy domains and mailboxes from the same vendor (pre-warmed Google, done-for-you Google, AirMail)
- You mainly use Google and Microsoft accounts, so the SMTP warmup-pool limit is unlikely to matter
- You need several workspaces on a higher plan, which its comparison table lists for Hypergrowth and above
Questions
Does Instantly really allow unlimited mailboxes?
Its pricing page and help centre say unlimited email accounts on paid plans. Its Terms of Service (updated 22 September 2026) also say it currently offers a maximum of 100 connected accounts per workspace, and its Standard Warmup Pool caps SMTP accounts by plan (100 on Growth).
What happens if I exceed Instantly's SMTP warmup limit?
The help centre says all accounts in the workspace, including Google and Outlook ones, move to the Basic Warmup Pool until you upgrade or buy add-ons. Changes apply daily at 12 am UTC.
Do hosted mailboxes count towards my Warmerly plan limit?
No. OneMail hosted mailboxes are billed per mailbox ($2.99, $1.99 or $0.99 a month depending on plan) and do not use a plan slot.
Can I use Warmerly just for warmup alongside Instantly?
Warmerly can warm mailboxes while another tool such as Instantly sends from them. Each mailbox still counts towards your Warmerly plan.
Sources
- Instantly pricing page
- Instantly Terms of Service
- Instantly Standard and Basic warmup pool
- Instantly email accounts dashboard
- Instantly account and campaign limits
- Instantly plans comparison
- Instantly plans overview
Instantly 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)
- Emails per month on starting plan
- Contacts on starting plan
- Warmup emails
- Spam-folder rescue interval
- Reply with quoted history
- Inbox placement seeds
- Health score timeline
- SPF/DKIM/DMARC monitoring
- Built-in campaign sender
- LinkedIn steps in the same sequence
- API access
- USD/GBP billing & customer data hosted in the EU
- Free plan / trial
- Try before you pay
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.