Built for cold-email agencies

Cold-email infrastructure, watched like vitals.

Mailnurse watches every sending account around the clock and fixes problems on its own. It replaces burned domains, swaps dead mailboxes, rewrites spammy copy, and rotates whole fleets. All automatically, before your campaigns ever feel it.

Start free → Book a demo

14-day free trial · No credit card · Bring your own Instantly

Trusted by cold-email teams running

Trusted by cold-email teams running Instantly, Smartlead, Email Bison, MailReach, GlockApps, and Mailmeteor.

01 · Auto health manager

It watches every account like an ICU monitor.

Mailnurse checks every account constantly: inbox placement, blacklists, and warmup health, and gives each mailbox a simple 0 to 100 health score. The moment one starts to slip, it pauses that account on its own, before a single bad mailbox can drag your whole campaign down.

  • A live health score for every account, refreshed around the clock
  • Pinpoints the exact mailbox dragging your inbox rate down
  • Pauses an account automatically the moment it starts to slip
How monitoring works →
02 · Replace burned accounts

Replace a burned domain in zero clicks.

When a domain is burned out, replacing it by hand takes about ten hours. Mailnurse does the whole job for you while you sleep: it buys a fresh domain, sets up the DNS, creates the mailboxes, connects them to Instantly, and starts warmup. You never touch a thing.

  • Burned mailbox? A ready-made persona, with name, photo, and identity, swaps in from a pre-warmed pool
  • The new domain warms up on schedule while the old one is retired cleanly
  • Every step is logged, so nothing is ever left half-finished
See auto-rotate →
03 · Auto-rotate the fleet

Set the policy. The whole fleet heals itself.

Picture two hundred accounts across twelve clients, all keeping themselves healthy. Mailnurse retires what's burned and stands up replacements across every workspace, so your sending capacity stays steady and no client quietly slips while you're busy with another.

  • Each client is fully separate, so one client's accounts never affect another's
  • New mailboxes spread evenly across your workspaces, automatically
  • One agency dashboard shows which client needs attention right now
See fleet management →
04 · AI copywriter

Rewrite burned copy in one click.

When a sequence stops landing, Mailnurse writes you a fresh one. You get full multi-step copy, checked against 360+ spam triggers, varied so every send looks a little different, personalized with the right details, and ready to push straight to Instantly. Old copy in, clean rewrite out.

  • Write a whole sequence from a short, one-time brief
  • Every line is spam-scored before it ever goes out
  • One click pushes the winning copy live to your campaign
See the AI copywriter →

Step 2 · Subject line

Variant A · burned → rewritten
Before · burned reply 0.4%

Re: FREE growth audit, guaranteed results!!!

spam score 7.8 FREEguaranteed!!!
After · rewritten reply 4.1% ↑

quick question about {{companyName}}'s Q3 pipeline

spam score 1.4 · 0 triggers {{firstName}}{{companyName}}{quick|fast}
AI-written · spam-checked · ready to push to Instantly
The full instrument panel

Seven ways cold email breaks. Mailnurse watches and fixes every one.

Each feature targets a specific reason emails stop reaching the inbox. Together, they keep your whole setup healthy.

01

Health monitoring

Constant inbox-placement tests, blacklist checks, and warmup vitals, rolled into one health score per account, so you see trouble coming before it hurts.

Learn more 02

Auto-rotate domains

When a domain burns out, Mailnurse replaces it end to end and starts warmup. The ten-hour job, done for you while you sleep.

Learn more 03

Auto-pause spam

When bounces climb, a blacklist hits, or placement drops, Mailnurse pauses the account before the damage spreads. Eight built-in rules decide when to act.

Learn more 04

Auto-replace mailbox

When a single mailbox burns out, Mailnurse retires it and drops in a ready-made persona, with name, photo, and identity, from a pre-warmed pool.

Learn more 05

AI copywriter

When a sequence stops landing, Mailnurse writes a fresh one: full multi-step copy, spam-checked against 360+ triggers, and ready to push to Instantly.

Learn more 06

Auto-placement

Mailnurse runs proven warmup schedules, adjusts send volume to engagement, and re-tests placement every night, so your inbox rate stays high on its own.

Learn more 07

Multi-tenant fleet

One dashboard for 200+ accounts across 12 clients. Every client kept fully separate, with agency-grade roll-up reporting and a white-label option.

Learn more
How it works

Three steps. Then it runs without you.

  1. 01

    Connect.

    Bring your Instantly, Workspace, and Cloudflare credentials. Two minutes. Once.

  2. 02

    Monitor.

    Mailnurse watches every sending account around the clock: placement, authentication, blacklists, and warmup health.

  3. 03

    Heal.

    When an account starts to slip, Mailnurse pauses it. When a domain burns out, Mailnurse replaces it end to end.

11
DNSBLs probed nightly
4 h
Vitals refresh cycle
8
Codified deliverability rules
360 +
Spam triggers checked per send
Pricing

Usage-based pricing that scales with your fleet.

No tiers and no sales calls. You only pay for the mailboxes you're managing, nothing else. Fourteen-day free trial, no credit card.

Managed mailbox

Core
$3 / mailbox / mo

Per Google Workspace account, metered to your live count. Monitoring + healing included.

Domain through us

$15 one-time / domain

Only if you want us to buy + provision it. Bring your own registrar and this is free.

Bring your own Instantly

$0 markup

Connect your existing Instantly account. We never resell it or touch your keys.

See full pricing →

Running 500+ mailboxes? Talk to us about volume

Works with the stack you already run

  • Instantly
  • Google Workspace
  • Cloudflare
  • Spaceship

Bring your own Instantly and Workspace. Mailnurse connects in a couple of minutes and never touches your keys.

Care, expressed as precision.

Cold-email infrastructure that watches itself, so you can focus on your campaigns instead of babysitting inboxes.

Start free trial → Book a demo

14-day free trial · No credit card · Instant setup