Replies land across a dozen mailboxes. NuMail pulls every one into a single inbox, classifies it the second it arrives, and writes the response in your voice, so you approve, not author.
Most tools poll IMAP every few minutes. NuMail subscribes to the source and gets pushed the event; median time from their send to your draft is 2.4 seconds.
Gmail mailboxes register a Cloud Pub/Sub watch on the inbox. Google pushes us a notification the instant a message lands: no polling window, no delay.
Microsoft 365 mailboxes use Graph subscriptions. Microsoft posts a change notification to our webhook the moment a new message hits the folder.
Generic SMTP/IMAP mailboxes hold an open IMAP IDLE connection. The server tells us the moment something arrives, near-real-time without a push API.
Six things working together so a reply goes from inbound to sent without you opening six tabs.
Every connected mailbox (Gmail, Microsoft, SMTP) collapses into one stream. No tab-switching, no "which account was that on." Replies are grouped by thread and de-duplicated across mailboxes.
2.4s median from their send to a notified, classified, drafted thread. Pub/Sub for Gmail, Graph notifications for Microsoft, IMAP IDLE as the fallback, never a polling lag.
Every reply is auto-sorted into positive, OOO, unsubscribe, question, or negative. Filter the inbox to "positive" and work only the replies that matter.
Claude reads the thread, the campaign it came from and the lead's own words, then writes a reply for you to approve. Nothing is sent without you: the draft waits in the Unibox until you accept, edit or reject it.
Read the draft, hit ⏎ to send, E to edit inline, R to reject. Clear fifty replies in the time it used to take to write five. Fully keyboard-driven.
Anything that reads as an opt-out is detected, the lead is added to your suppression list, and they're removed from every active sequence, automatically, before another email can go out.
Generic AI replies read like AI replies, and prospects can tell. NuMail trains on your actual sent mail so the draft is one you'd have written anyway.
Every reply is classified before anything is drafted, so an out-of-office, an unsubscribe and real interest are told apart. What Claude drafts is the reply to the one that matters, with the thread and the campaign it came from in front of it.
Every reply is generated against that profile and scored for voice match, so a draft that doesn't sound like you is obvious before you send it. Nothing is ever sent without you: the score tells you about tone, not about whether the answer is right.
{
"thread_id": "thr_2c1",
"classification": "positive",
"latency_ms": 2400,
"draft": {
"id": "drf_9a4",
"voice_match": 0.94,
"length": "short",
"body": "Hey Sarah, great timing.
Onboarding's usually about
a week…"
},
"actions": ["approve", "edit", "reject"]
}
# Approve & send in one call:
POST /v1/unibox/thr_2c1/approveSmartLead and Instantly bolted a unibox onto a sender. NuMail built reply-handling as the product: faster detection, real drafts, true unification.
Connect your mailboxes, let NuMail learn your voice, and clear your whole inbox in keystrokes. 14-day trial, no card.