Connect a mailbox

OAuth in 60 seconds, or SMTP for any provider.

Need a fresh fleet? Get 100 ColdRelay mailboxes for $50.

Domains, DNS, SPF, DKIM, DMARC — all provisioned in 2–4 hours. First month half off. Mailboxes auto-attach here when ready.

Or connect your own

OAuth is one click. SMTP needs a host/port + creds.

Gmail Workspace

OAuth · uses the Gmail API. Real-time reply detection via Pub/Sub.

Recommended

Microsoft 365

OAuth · Microsoft Graph subscriptions for real-time push. Auto-renewing.

Generic SMTP / IMAP

Host, port, username, password. IMAP IDLE for reply detection. Works with everything.

ColdRelay-provisioned mailbox

Pre-warmed mailbox from your existing ColdRelay account. One-click attach.

You'll be sent to Google to approve scopes. We never see your password.

We request gmail.send, gmail.readonly, and Pub/Sub watch scope. Revoke any time from Google account settings.

After authorising, you'll come back to this wizard to send a test email.

We'll send a real email to confirm authentication works end-to-end.

Send test to

Subject

Delivered in 1.4s

Headers verified · SPF pass · DKIM pass · DMARC pass. You're good to send.

Conservative defaults — we'll auto-increase as your reputation builds.

From name

From address

Daily send limit

Includes both campaign + warmup sends.

Send window

Warmup

Cross-sends to other mailboxes to build sender reputation.

Daily warmup target

Pool

Skip weekends

No campaign sends Saturday + Sunday in recipient's local timezone.

Mailbox enrolled in shared warmup pool · Bronze → Silver in 14 clean days · Silver → Gold in 30. Add it to a campaign pool when you're ready.

Back to mailboxes Use in a new campaign