Free email warm-up,for everymailbox.
Connect any mailbox, from Google Workspace, Gmail or any other provider, and it warms up on mailzy's own network for free. No plan, no card and no limit on mailboxes. Paying customers can move any mailbox to our premium pool.
Real conversations between real mailboxes.
Your mailbox writes to other mailboxes in the network and hears back from them. Every warm-up email is found, opened, moved out of spam, marked important and answered, the way a person would, so mail providers see a mailbox people want to hear from.
Aged Google and Microsoft mailboxes, at no extra cost.
On a paid plan, move any mailbox to the premium pool, or back again, with one click. A mailbox is never warmed in both at once, and if you stop paying it moves back to the free network by itself.
See where your email really lands.
Send one email to our test mailboxes at Gmail, Yahoo and other providers, and see whether each reached the inbox, promotions or spam, with SPF, DKIM and DMARC as each provider saw them. Two tests are free. Paid plans test every mailbox once a week with its latest campaign email, and tell you if one lands in spam.
The details.
Health score
The share of warm-up emails that reached the inbox over the last 7 days, with what was saved from spam and where each provider put them.
Your settings
Daily limit, how fast it grows, reply, open and rescue-from-spam rates, and weekdays only. For one mailbox or many.
Your warm-up sign-offs
Every warm-up email ends with one of your own sign-off names, a different one each time, with nothing in the subject, so no single code marks it. One filter on the names keeps them out of your inbox. Step-by-step guides for Gmail and Outlook.
A clean network
Mailboxes failing SPF or DMARC, landing in spam or unable to sign in are held until they're fixed, so you only warm with healthy partners.
Keeps going during campaigns
Campaign mode lowers warm-up to 10 a day once a mailbox runs your campaigns, so the rest of the day is theirs.
Written like people
Varied, plain business emails from our library, and AI-written threads for paying customers' mailboxes, checked against a list of phrases nobody should send.
Only warm-up emails
Warm-up touches only its own emails, each found by its ID. Your other mail is never read, moved or stored.
Ready for campaigns
A checklist says when a mailbox is ready: DNS valid, not blacklisted, warmed for 14 days and health above 85.
Questions before you start.
Ask us on the chat if yours isn't here. A real person answers.
Is warm-up really free?
Yes. Sign up, connect a mailbox and switch warm-up on. No plan, no card and no limit on how many mailboxes.
What's the difference between the free network and the premium pool?
The free network is mailzy's own, shared by every customer's mailboxes. The premium pool is made of aged Google and Microsoft mailboxes and is included on paid plans. You choose per mailbox and can switch back any time.
Do you read my email?
No. Warm-up works only on warm-up emails, each found by its own ID. Your other mail is never read, moved or stored.
Which mailboxes can I warm up?
Any mailbox you can connect: Google Workspace and Gmail, and any provider over SMTP and IMAP, including mailboxes you didn't buy from us. Microsoft 365 and Outlook are coming soon.
How long should I warm a mailbox before sending?
At least 14 days, with a health score above 85. The readiness checklist tells you when a mailbox is ready.
Should I keep warming once campaigns start?
Yes, at a lower level. Campaign mode keeps 10 warm-up emails a day running beside your campaigns.
Do I need email warm-up?
Yes for a new mailbox, because it has no history and sending straight to strangers gives it a bad one. An older mailbox with normal email behind it needs less time, but warm-up still helps keep its reputation steady.
How does email warm-up work?
Mailboxes in the network email each other, open the emails, reply, mark them as important and move them out of spam if they land there. Mail providers see normal, wanted email, and the volume rises gently.
Does warm-up alone fix deliverability?
No. It builds reputation, but a bad list, broken DNS records or too much volume can still put you in spam. Warm-up works alongside them, not instead of them.
Everything for cold email, in one place.
Start free for 14 days. No card needed.