Connecting your inbox

Last updated: 25 April 2026

Tendo sends approved replies from your inbox — never a Tendo-branded address. You connect once during setup; from then on every approved reply ships from your address with your domain reputation. This page covers the three connection options.

Which to pick

• Gmail / Google Workspace — easiest if you run on Google. OAuth, no passwords. Recommended.
• Microsoft 365 / Outlook — easiest if you run on Microsoft. OAuth, multi-tenant.
• SMTP — for Fastmail, Zoho, ProtonMail Bridge, custom mail servers, or Workspace accounts whose admin policy blocks OAuth. Requires a username + password (often an "app password" — see below).

Gmail / Google Workspace

1. Open Tendo in your Shopify admin → Email in the left nav.
2. Click Connect Gmail. A new tab opens with Google's consent screen.
3. Sign in with the Google account you want to send from. Approve the requested scopes:
   • gmail.send — send mail. We never read your inbox.
   • gmail.metadata — read message headers (only) of mail Tendo just sent, so customer replies thread correctly.
   • email, openid — confirm which address you authorized.
4. You'll land on a Tendo confirmation page. Click{" "} Return to Tendo — the Email settings page will now show "Connected — sending from you@yourstore.com".

If your Workspace admin blocks third-party OAuth: ask them to allowlist Tendo, or use the SMTP option below with an app-password.

Microsoft 365 / Outlook

1. Open Email in Tendo, click{" "} Connect Microsoft 365.
2. Sign in with the Microsoft account you want to send from (work, school, or personal Outlook all work).
3. Approve the requested scopes:
   • Mail.Send — send mail. We never read your inbox.
   • offline_access — refresh tokens so we don't prompt you to re-auth every hour.
4. If your tenant requires admin consent, Microsoft will route you through that flow automatically.

SMTP

Use this for Fastmail, Zoho, ProtonMail Bridge, custom mail servers, or Google Workspace / M365 setups where OAuth isn't an option. Tendo verifies your credentials against the SMTP server before saving — if the credentials are wrong, the save fails immediately rather than at send time.

1. Open Email in Tendo, click{" "} Set up SMTP.
2. Fill in the form using your provider's SMTP settings:
   • Host — usually{" "} smtp.your-provider.com.
   • Port — 587 for STARTTLS (most common) or 465 for implicit TLS. Tick "Use implicit TLS" only for port 465.
   • Username — usually your full email address.
   • Password — your account password,{" "} or an app-specific password if your provider requires one.
   • From address — the address customers will see in the From: header. Must match what your SMTP provider allows you to send as.
3. Click Verify and save. Tendo opens an SMTP connection, tries to authenticate, then closes it. Bad credentials show a clear error so you know to fix them before any real mail is queued.

App-password notes

• Gmail — generate at{" "} myaccount.google.com/apppasswords . Requires 2FA enabled on the account. Some Workspace accounts disable this entirely; use OAuth instead.
• iCloud / Apple Mail — generate at{" "} account.apple.com{" "} → Sign-In and Security → App-Specific Passwords.
• Yahoo — Account Security → Generate app-password.
• Most other providers — search "[provider] app password" and paste here.

Disconnecting

Open Email in Tendo and click{" "} Disconnect. We revoke OAuth tokens at the provider where possible (Gmail), then delete our local copy. Approved-but-not-yet-sent drafts remain queued; they'll deliver once you reconnect.

What customers see

Outbound replies show:

• From: your connected address — you@yourstore.com.
• Reply-To: a per-store Tendo inbound address. When the customer hits Reply, their mail client targets that address; the reply lands in Postmark and threads back to the same Tendo ticket. Customers never see anything Tendo-branded in their primary view.
• Subject: Re: original subject.

Troubleshooting

• "Email authorization expired" banner — your provider revoked the token. Disconnect + reconnect from the Email page.
• "No sending address connected" on a ticket{" "} — the inbox was disconnected after the draft was created. Reconnect, then click Retry send on the failed action.
• Reply landing as a new ticket instead of threading{" "} — if you're on Gmail and have an old connection, disconnect and reconnect to grant the gmail.metadata scope (added April 2026). Threading via subject-fallback handles older connections, but the canonical path is more reliable.