Features

A complete cold email platform.

Sending, deliverability, warmup, unified inbox, AI copywriting, integrations, analytics — all built to talk to each other so your sequences actually reach humans.

Sending engine

Volume that scales without raising flags

Account rotation

Round-robin across every connected sending account with least-recently-used balancing.

Daily limit + ramp-up

Per-account daily caps with daily +N ramp-up curves so new domains warm up gracefully.

Sending hours + timezone

Restrict each account to specific business hours, days of week, in any IANA timezone.

Spintax + variables

Mustache `{{firstName}}` syntax + `{a|b|c}` spintax produces a unique payload per send.

Stop on reply / auto-reply detect

Live IMAP IDLE listener kills follow-ups the moment a real human replies.

Plain-text mode

One toggle to send plain-text only — historically the highest-deliverability format.

Deliverability tooling

Inbox placement is a science we automate

Domain Health Center

Bulk SPF, DKIM, DMARC, MX, RBL, TLS-RPT checks across every account in one click.

Per-record fix guides

Provider detection (Cloudflare, GoDaddy, Namecheap, Route 53) ships specific setup steps.

Spam test

Send to 10+ seed inboxes (Gmail, Outlook, Yahoo, Zoho, Proton, AOL) and see exact placement.

Content score

Caps detection, spam-keyword analysis, link density, image-only detection — 0-100 score with issues.

Custom tracking domain

Self-service CNAME setup so opens and clicks ship from your subdomain.

Suppression list

Hard bounces, complaints and unsubscribes auto-suppress workspace-wide.

Unified inbox

Reply where you outreached

IMAP IDLE listener

Persistent TCP connection per account → replies appear in 60 seconds or less.

Reply matching

In-Reply-To / References header matching plus subject-line fallback to link replies to the right campaign lead.

Auto-reply detection

Out-of-office and `Auto-Submitted: auto-replied` headers logged but never treated as engagement.

Status tagging

Tag threads as Interested / Meeting Booked / Not Interested / Out Of Office / Wrong Person.

Real-time UI

WebSocket bridge pushes new replies into the unibox without a refresh.

Reply via SMTP

Reply directly from MailFlow — message threads correctly via Message-ID + References.

Email warmup

Build reputation while you sleep

Cross-tenant pool

Workspace accounts (with consent) form an organic warmup pool sending realistic conversation.

IMAP-only manipulation

Move-from-spam, mark-important, threaded replies — all via standard IMAP MOVE / STORE / SEARCH.

Quality scoring

Higher-reputation accounts pair preferentially with higher-reputation accounts.

Daily target slider

Per-account warmup target with per-day ramp-up; reply-rate setting from 0% to 100%.

Hidden mailbox

Warmup messages auto-route to a `MailFlow-Warmup` IMAP folder — your inbox stays clean.

Template variety

Multi-thousand template pool plus AI-generated variations to mimic real human conversation patterns.

Campaign builder

A/B test everything that matters

Multi-step sequences

Up to 7 steps with custom delay-days. Stop conditions are per-campaign.

A/B variants

Multiple variants per step with weighted distribution; track open / click / reply per variant.

AI sequence assistant

Goal + audience + tone + length → fully written sequence in 5 seconds.

Inline rewrite

Per-step "shorter / warmer / sharper CTA" rewrites without leaving the editor.

Live preview

See a rendered email — variables filled, spintax resolved — before launching.

Schedule windows

Per-campaign day-of-week + hour-of-day sending windows.

Analytics

Numbers that reveal what to do next

Per-campaign funnel

Sent → Opened → Clicked → Replied with conversion rates at each stage.

Per-step breakdown

Identify which step in your sequence is doing the heavy lifting.

Per-account performance

Bounce rate, complaint rate, reply rate per sender — kill underperforming accounts before they spread.

Time-of-day heatmap

See which hours generate replies in your audience.

A/B significance

Statistical significance markers on variant winners.

Real-time tick

Sent counter ticks live — no need to refresh.

Platform

For teams that grow past one person

Multi-workspace

Belong to multiple workspaces. Switch with one click.

Roles

Owner / Admin / Member. Granular access to credentials and billing.

Audit log

Every sensitive action logged with actor, IP and metadata.

Webhooks

HMAC-signed payloads. Retries with exponential backoff. Per-event filtering.

REST API

Workspace-scoped API keys with bcrypt-hashed storage and prefix lookup.

Cmd+K command palette

Linear-style global search to navigate or take action without ever leaving the keyboard.

Built for the way your team actually works.

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