Adaptive ramp-up curve
Volume grows from 2-5 emails a day to 30-50 in two to four weeks. It slows on spam signals and speeds up on clean ones, with preset curves for a new domain, an aged domain and recovery.
Email warm-up
Warm-up that looks human, and proves it worked.
Short answerRoxInbox email warm-up builds the reputation of new and cold mailboxes in two to four weeks. It sends real conversations that are opened, replied to and rescued from spam across every major provider, then keeps warming in the background.
Why warm up
New mailboxes look like spammers until they prove otherwise.
Mailbox providers judge a sender on three things: authentication (SPF, DKIM and DMARC), history and volume (domain age, and whether sending grows gradually), and recipient reactions (opens, replies, complaints and messages rescued from spam).
A brand-new mailbox has no history and no reactions. If it sends hundreds of messages on day one, filters treat it as a spammer. Warm-up builds the missing history and reactions on purpose, slowly, so the mailbox earns a reputation before your real campaigns depend on it.
RoxInbox checks authentication first, then builds the other two.
How RoxInbox warms
Built to keep working as filters get smarter.
Simple ping-pong networks are losing their value because large providers can spot them. RoxInbox is designed around that problem.
AI-written conversations
Threads are written for each mailbox's industry and language, in 100+ languages. No links, no attachments, no spam triggers, and global n-gram deduplication so no two threads read alike.
Human behaviour
Network mailboxes open, reply to 40-60% of messages, rescue mail from spam, star and archive, during working hours in each mailbox's time zone, with natural delays.
Anti-fingerprint network
The network is split into isolated segments of 500-1,000 mailboxes. Accounts are real, aged and live on real domains. Each mailbox keeps one stable IP.
No provider above 40%
Reputation is built across every major provider at once, so a policy change at one of them can't erase the network's value.
Auto-pause on risk
If a mailbox's spam rate climbs, RoxInbox holds or pauses its volume and alerts you by email and Slack before it does lasting damage.
What the network does
Every action happens on a human schedule.
| Action | Why it matters | How it stays natural |
|---|---|---|
| Open | An engagement signal that clears the “unwanted” flag | 5 minutes to 6 hours after delivery, and never for every message |
| Move from spam to inbox | The strongest signal: it tells the filter it was wrong | Only when a message really landed in spam |
| Reply in thread | Two-way conversation looks like a real contact | 40-60% of messages, hours later, replies that follow the thread |
| Star or mark important | Extra positive signal | 10-20% of messages |
| Archive | Imitates normal inbox housekeeping | 1-7 days later |
Providers
Warm-up on the providers your recipients actually use.
- Outlook / Microsoft 365 →
- Google Workspace →
- Yahoo Mail →
- Zoho Mail →
- iCloud Mail →
- Mail.ru →
- Yandex Mail →
- GMX / WEB.DE →
- Corporate SMTP →
Already sending with an outreach tool? RoxInbox runs alongside Instantly, Smartlead, lemlist, Apollo and HubSpot.
FAQ
Email warm-up questions
What is an email warm-up tool?
An email warm-up tool builds the sending reputation of a new or cold mailbox by sending a small, slowly growing number of real-looking emails that other mailboxes open, reply to and mark as not spam. Providers read that engagement as a sign the sender is trusted.
How long does email warm-up take with RoxInbox?
Most new domains reach a working volume of 30-50 emails a day per mailbox in two to four weeks. Aged domains are usually faster; domains recovering from a block take longer. The ramp adjusts itself to each mailbox's signals.
Should I keep warm-up running after the ramp?
Yes. After the plateau RoxInbox keeps warming in the background at about 20-30% of your sending volume. Stopping warm-up entirely is one of the most common reasons reputation fades a few weeks after a campaign starts.
Can I run campaigns while a mailbox is warming up?
Wait until the mailbox reaches its plateau and passes a placement test. Sending a campaign in the first two weeks puts the reputation you are building at risk.
Does warm-up work for Outlook and Microsoft 365?
Yes. Microsoft 365 mailboxes connect by OAuth, and Outlook is one of the providers in the network with its own seed mailboxes for placement tests. See the Outlook warm-up guide.
Is warm-up the same as a placement test?
No. Warm-up builds reputation over time; a placement test measures it at a point in time. RoxInbox includes both, so you can see the effect of warm-up instead of guessing.
Want the full picture? Read the complete guide to email warm-up, or see how RoxInbox works step by step.
Start warming up in five minutes.
Connect a mailbox, let RoxInbox check your DNS, and watch its placement climb.