Cold email outreach
without the spam folder.
Connect unlimited Gmail, Outlook or SMTP accounts, warm them up automatically, and run multi-step campaigns with rotation, deliverability tools, AI copywriting and a unified inbox — all in one place.
No credit card required · 1-minute setup · Cancel anytime
Q3 Outbound · Series A founders
RUNNINGTrusted by 4,200+ growth and sales teams
The problem
Most cold email tools land in spam.
Shared IPs, unverified senders, generic templates and zero warmup all guarantee one thing: your perfectly written outreach disappears into the Promotions tab — or worse, the Spam folder. MailFlow fixes deliverability at the protocol level so your emails actually reach the inbox.
Features
Everything you need, nothing you don't.
Connect any inbox
Gmail, Workspace, Outlook 365, Zoho, Yahoo, ProtonMail Bridge, custom SMTP — all via App Password. Zero Google verification.
Automatic warmup
Cross-tenant pool that gradually builds your sending reputation through standard IMAP commands. No black-box APIs.
Multi-step sequences
A/B variants, spintax, mustache variables, smart delays, stop-on-reply, daily limits per account.
Account rotation
Round-robin across your sending pool with per-account ramp-up curves and timezone-aware scheduling windows.
Unified inbox
Real-time replies via persistent IMAP IDLE connections — see every conversation across every connected account in one view.
AI sequence assistant
Generate full multi-step sequences from a goal, or rewrite individual steps shorter / warmer / punchier.
Domain Health Center
One-click bulk SPF / DKIM / DMARC / MX / RBL / TLS-RPT checks across every connected account.
Spam test
Send to 10+ seed inboxes and see exactly where you land — Inbox, Promotions, Spam — for Gmail, Outlook, Yahoo and more.
Custom tracking domain
Self-service CNAME setup so opens and clicks ship from your own subdomain — never a generic shared URL.
Bounce + complaint handling
DSN parsing classifies hard bounces, soft bounces and FBL complaints, then auto-suppresses across the workspace.
Webhooks + REST API
Subscribe to lead.replied, campaign.completed and a dozen more events. HMAC-signed payloads, retries, delivery log.
Team collaboration
Multi-tenant workspaces, role-based access, audit log, shared sender accounts, seat-based billing.
How it works
From sign-up to first reply in 15 minutes.
Connect your inbox
Paste an App Password. We test SMTP + IMAP + a loopback message in under 30 seconds.
Run domain health
One click checks SPF, DKIM, DMARC, MX, RBL and TLS-RPT — with per-issue setup guides.
Build your sequence
Generate it with AI or write your own with variables and A/B variants. Preview before launch.
Launch and manage replies
Sends throttle automatically. Replies stream into the unified inbox — answer right from MailFlow.
Deliverability
We obsess over inbox placement so you don't have to.
- ✓IMAP-only inbox manipulation — never the Gmail API. No restricted scopes, no CASA assessment, no 100-user cap.
- ✓Per-account daily limits + ramp-up so new domains never hit volume cliffs.
- ✓Spintax + mustache variables vary every send so identical content never hashes the same way twice.
- ✓Automatic suppression list across the workspace — bounces and unsubscribes never get retried.
- ✓List-Unsubscribe and one-click unsubscribe headers shipped on every send.
SPF · DKIM · DMARC · MX · RBL · TLS-RPT — bulk-checked across every connected account in 8 seconds.
Plays well with everyone
Connect every email account you own.
All providers connect through standard SMTP + IMAP with App Passwords. Zero OAuth restricted-scope drama.
Loved by operators
Reply rates speak for themselves.
We went from 1.4% reply rate on a competitor to 8.6% in our first 30 days. The warmup actually works.
The Domain Health Center caught a missing DKIM record across 12 domains in seconds. Saved us a quarter of complaints.
Connecting 24 sender mailboxes used to be a 2-day project. With MailFlow it took an afternoon — App Passwords, no OAuth circus.
Why MailFlow
Built differently, for a reason.
| Capability | MailFlow | Typical incumbent |
|---|---|---|
| Restricted Google scopes | Never | Required |
| CASA verification annual cost | $0 | $500–2,500 |
| 100-user cap on unverified scopes | N/A | Hard limit |
| Connection method | SMTP + IMAP App Password | OAuth + Gmail API |
| Inbox manipulation for warmup | Standard IMAP commands | Provider-API dependent |
| Bring your own tracking domain | Self-service CNAME | Paid add-on |
| AI sequence assistant | Built-in | Add-on / 3rd-party |
Pricing
Plans that scale with your sending.
14-day Growth trial included. Switch tiers any time. No setup fees.
Frequently asked.
Why don't you use the Gmail API?+
Because Google requires a $500–2,500/year CASA security assessment for restricted scopes — and caps unverified apps at 100 users. SMTP + IMAP with App Passwords is RFC-standard, requires zero verification, scales to unlimited users, and gives us everything we need (send, receive, search, move, flag).
Will my emails land in spam?+
Deliverability comes down to your sender reputation and your DNS. We help on both: automatic warmup builds reputation gradually, and the Domain Health Center forces you to fix SPF/DKIM/DMARC before launch. Most users see inbox rates above 80% within 3 weeks.
How does warmup actually work?+
Your account joins a cross-tenant pool. Other workspace accounts send your inbox normal-looking emails, MailFlow opens them, replies, marks important, and moves anything from spam back to inbox — all via standard IMAP commands. Provider reputation systems treat this as engaged human activity.
Can I bring my own SMTP?+
Yes. Custom SMTP/IMAP credentials work for any RFC-compliant mail server: Postmark, Amazon SES, your own Postfix, ProtonMail Bridge, etc. We support STARTTLS and SSL on any port.
Is there an API?+
Yes — REST + webhooks. Generate a workspace key, hit the endpoints with Bearer auth, subscribe to lead.replied, campaign.completed, email.bounced and a dozen more events. Webhook payloads are HMAC-signed.
What about CAN-SPAM and GDPR?+
Every send carries a List-Unsubscribe header + visible footer. Suppressed addresses are tracked workspace-wide. We expose data export + deletion endpoints, ship a DPA, and the encryption layer (AES-256-GCM) protects all credentials at rest.
Start sending mail that lands.
14-day Growth trial. Connect your inbox in 60 seconds. Cancel anytime — no card needed.