Connect a mailbox (Gmail, Outlook, SES, SMTP)

Provider-by-provider connection steps, what Test connection actually checks, and how credentials are stored.

Every message SendCanyon sends goes out through a mailbox you own, using that mailbox's own provider — there is no shared sending infrastructure to inherit someone else's reputation from. Connect mailboxes under Mailboxes → Connect mailbox and pick your provider.

Gmail / Google Workspace

Choose Google, and either sign in with OAuth (recommended — no password stored, revocable from your Google admin console) or use an app password if your organization restricts third-party OAuth. For app passwords you'll need 2-step verification enabled on the account; generate one at myaccount.google.com → Security → App passwords and paste it into the SMTP password field with server smtp.gmail.com, port 587.

Microsoft 365 / Outlook

Choose Microsoft and complete the OAuth consent flow. If your tenant requires admin consent for third-party apps, your Microsoft 365 admin will need to approve SendCanyon once; after that, individual mailboxes connect in two clicks. SMTP AUTH must be enabled for the mailbox (Microsoft admin center → Users → Mail → Manage email apps).

Amazon SES

Choose Amazon SES and provide your SMTP credentials (generated in the SES console under SMTP settings — note these differ from your IAM keys), the region endpoint (for example email-smtp.us-east-1.amazonaws.com), and the From address. Your SES account must be out of the SES sandbox and the From domain verified inside SES as well as in SendCanyon.

Any SMTP provider

Choose Custom SMTP for any other provider. You'll need: SMTP host, port (587 with STARTTLS preferred, 465 for implicit TLS), username, password, and the From address. SendCanyon uses this connection to send only — it does not read your mailbox. See how replies reach SendCanyon for what that means for stop-on-reply.

What Test connection checks

  1. Authenticates against the SMTP server with the stored credentials, for SMTP and Amazon SES mailboxes.
  2. For Google and Microsoft mailboxes, confirms the stored credentials are complete — the first warmup send is the live check.
  3. Records the From address and daily cap the mailbox will send under.

A mailbox only becomes eligible for sending after the test passes. Re-run it any time from the mailbox's detail page — if a password rotates or OAuth is revoked, the mailbox flips to Connection error and is skipped by campaigns until fixed.