Warmerly
Not published.
Warmerly
Mailivery
One-to-one · Warmup network size
Warmup network size
One row, in depth: what each tool does, the verified numbers, and who each suits.
Mailivery details read from its pricing page, home page, product pages and API page on 21 October 2026.
Warmerly
Not published.
Mailivery
100,000+ active mailboxes, as its warm-up page states.
The short answer
Warmup network size, in one look.
Warmerly does not publish a network size, so we cannot compare the two sizes, while Mailivery's warm-up page states 100,000+ active mailboxes. Mailivery's warm-up page states 100,000+ active mailboxes and says every inbox is verified daily. Warmerly does not publish a network size, so we cannot compare the two sizes. What we can show is how mail is paired: threaded replies, no repeat to the same recipient inside 72 hours where the pool allows, and a per-mailbox cap however many partners there are. Neither size has been checked by a third party. Last checked 22 October 2026.
MailiveryMailivery ahead on this row
100,000+ active mailboxes, as its warm-up page states.
The picture
Drawn side by side.
The network, as each page states it
Not a scale for Warmerly's network, which we do not publish
WarmerlyMailivery
Not published
- Much smaller than Mailivery's
- Pairing rules published
- Gmail 40, Outlook 30, Zoho 25 a day
100,000+ mailboxes
- Every inbox verified daily, per its page
- Accounts showing spam behaviour removed
- Real inboxes, not bots
Mailivery figures are its own statements, read on mailivery.io/email-warm-up on 21 October 2026. Neither network has been checked by a third party.
How a warmup email travels
The steps each page describes
WarmerlyMailivery
Warmerly
Send to a real mailboxRecipient opensReply that quotes the threadRescued if in spam
Mailivery
Connect your mailboxNetwork sends and opensPositive reply, marked importantMoved out of spam
Warmerly threads go to a depth of 3, and a sender does not write to the same recipient twice within 72 hours.
How Warmerly does it
Warmerly, in detail.
A smaller peer pool, with no headline number, a published pairing rule and a published cap on what each mailbox sends.
01
No published size
We do not publish a network size, and the network is smaller than the figure Mailivery states.
Warmerly product, checked 21 October 2026
02
Threaded warmup emails
Warmup mail goes between real mailboxes in one pool, including other customers' mailboxes. The recipient opens, replies and quotes the earlier message, up to a thread depth of 3.
Warmerly product, checked 21 October 2026
03
Repeat contact is limited
A sender does not write to the same recipient twice within 72 hours, relaxing to 48 and then 24 if the pool runs short.
Warmerly product, checked 21 October 2026
04
A cap on what each mailbox sends
A mailbox's warmup quota is held to 40 a day on Gmail, 30 on Outlook and 25 on Zoho, however large the pool is.
Warmerly product, checked 21 October 2026
05
Who gets picked as a recipient
A recipient is weighted by three factors: how few jobs it already has today, how few emails this sender has already sent to its provider today, and how much that recipient itself sends. That spreads volume across the pool and across providers.
Warmerly product, checked 21 October 2026
06
The 72 hour rule gives way before volume does
If a sender runs out of eligible partners, the no-repeat window narrows for that sender from 72 to 48 and then 24 hours, never lower. A sender doing N emails a day needs roughly 3N distinct partners inside a 72 hour window.
Warmerly product, checked 21 October 2026
07
Sent and received stay close to balanced
Because every warmup job has one sender and one recipient, total sent equals total received across the pool. Weighting recipients by their own quota pulls older mailboxes' received count up toward what they send, which looks more like a real inbox.
Warmerly product, checked 21 October 2026
08
Our own brand domain is kept out
Mailboxes on Warmerly's own brand domain neither send nor receive warmup mail, so the pool never looks like a stream of mail from our own name.
Warmerly product, checked 21 October 2026
09
When the pool is short, it says so
A sender that cannot fill its quota is logged, with a different message for a pool at its limit and a pool too small to serve the demand. The fix named in our own notes is more mailboxes in the pool.
Warmerly product, checked 21 October 2026
How Mailivery does it
Mailivery, in detail.
A network it sizes at 100,000+ active mailboxes, described as real inboxes that are verified daily, with the sourcing left unexplained.
01
100,000+ active mailboxes
The warm-up page cites a 100K+ mailbox network and 100,000+ active mailboxes.
mailivery.io/email-warm-up · read 21 October 2026
02
Real inboxes, verified daily
The page says Every inbox in our network is verified daily, and that accounts showing spam behaviour are removed.
mailivery.io/email-warm-up · read 21 October 2026
03
Peer to peer
Its pricing FAQ describes real peer-to-peer email accounts, not just bots.
mailivery.io/pricing · read 21 October 2026
04
Dedicated folders
Warm-up activity is kept in dedicated folders so it does not get in the way of your sales activity.
mailivery.io · read 21 October 2026
05
A network with a stated bounce rate
The warm-up page says bounce rate stays under 0.1% and that most users see zero, and that invalid or inactive addresses are removed before they touch your account.
mailivery.io/email-warm-up · read 22 October 2026
06
Templates are watched
It says warm-up templates are monitored and rotated, and underperforming content is pulled.
mailivery.io/email-warm-up · read 22 October 2026
07
Who is in the network
It says your emails interact with real business accounts, marketing platforms, CRM users and email accounts across Gmail, Yahoo and more, not only cold emailers warming up with other cold emailers.
mailivery.io/email-warm-up · read 22 October 2026
08
Clean-up of bad accounts
It says any account in the network that shows spam behaviour or reputation issues is removed.
mailivery.io/email-warm-up · read 22 October 2026
09
Partners named on its pages
Its warm-up page names Winnr, Automailer, Woodpecker, MeetChase and MailClickConvert as platforms that trust it, and says Woodpecker and Skylead build warm-up in with Mailivery.
mailivery.io/email-warm-up · read 22 October 2026
What Mailivery does not say
We looked, and found no statement on these. That is about its published pages only, not about the product.
- How network accounts are sourced
- Whether the owners of those mailboxes consent to take part
- Any independent audit of the network size
- The mix of providers inside the 100,000+ mailboxes
- How many mailboxes any one customer is paired with
- Whether the mailboxes belong to other customers, to Mailivery or to partners
Where the sources disagree
We report each version rather than pick one.
- Customer counts: its home page says 1,000+ companies and individuals, while its warm-up page says 2,000+ companies. Neither is independently checked.
- Quality claims: its warm-up page says the network has under 0.1% bounce rate and no cold emailer echo chamber, and its pricing FAQ calls the network peer to peer. Neither says how the mailboxes are recruited.
The numbers
Only what we could verify.
| Measure | Warmerly | Mailivery |
|---|---|---|
| Warmup network size | Not published. | 100,000+ active mailboxes, as its warm-up page states. |
| Network size | Not published | 100,000+ active mailboxes |
| Same recipient twice | Not within 72 hours | Not stated |
| Network accounts verified | Not stated | Daily, per its page |
| Repeat contact rule | 72 hours, relaxing to 48 then 24 if short | Not stated |
| Bounce rate on warm-up | Not published | Under 0.1%, per its page |
| Threaded replies | Up to a depth of 3 | Replies and moves from spam to inbox, depth not stated |
| Customers named | Not published | 1,000+ on its home page, 2,000+ on its warm-up page |
In practice
What it means for you.
Our reading of the facts above. Not a promise, and not the only reasonable reading.
Size matters at volume
A larger pool gives more varied partners at high volume. At 5 to 25 mailboxes it is rarely the first limit.
Treat both claims as claims
Neither network size has been checked by a third party.
What a sender needs in partners
Using Warmerly's own rule of about three partners for each email a day, a mailbox at the top of the ramp, 50 a day, needs around 150 distinct partners inside 72 hours. That is a long way below 100,000, so a very large network is not the limit for one mailbox. It matters when hundreds of mailboxes draw on the same pool at once.
A fleet is where size shows
Mailivery's examples run 60 to 80 mailboxes on one plan. A pool that big only works if the network behind it is large, which is the case for a stated 100,000+ and harder for a small pool. If you plan to warm well beyond a hundred mailboxes, ask each service how it keeps partners varied.
Ask about the sourcing
Neither side explains who owns the other mailboxes in the pool. Mailivery says real inboxes and daily checks. Warmerly says its pool includes other customers' mailboxes. Before you join either, ask what the owners of those mailboxes agreed to.
Clean network or large network
Mailivery's page puts weight on removing bad accounts and a bounce rate under 0.1%. Warmerly keeps a list of low-reputation recipient domains out of hosted senders' choices. Both are claims about quality, and quality is harder to see from outside than size.
Who it suits
Pick the one that fits.
Warmerly
Warmerly is the better fit if
- You send a modest volume from 5 to 25 mailboxes
- You want the pairing rules published
- You want pairing rules written down, including how they relax when the pool is short
- You prefer replies that quote the earlier message in a thread
Mailivery
Mailivery is the better fit if
- You run a large fleet and want the bigger stated network
- You want daily verification of network accounts
- You expect to warm well beyond 100 mailboxes
- You want a network said to be checked daily for bad accounts
Questions
How big is Warmerly's network?
We do not publish a number, so we cannot set it beside Mailivery's stated 100,000+ mailboxes.
Who is in Mailivery's network?
Its pages say real inboxes, not bots, verified daily. They do not say how the accounts are sourced.
Does Warmerly send warmup to the same address twice in a row?
A sender avoids the same recipient for 72 hours. If it runs out of partners, that narrows to 48 and then 24 hours, and no lower.
Does Warmerly use other customers' mailboxes?
Yes. Warmup mail goes between real mailboxes in one pool, including other customers' mailboxes.
Is a bigger network always better?
No. It gives more varied partners at high volume. For a few mailboxes, the pairing rules and the quality of the partners count for more than the headline number.
Sources
Mailivery pages were read on 21 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
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.
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