Connect a Microsoft 365 / Outlook mailbox to OutreachFox

Connect a Microsoft 365 or Outlook mailbox so OutreachFox can send campaign and warmup email from it and read replies. This is the OutreachFox-side part of the setup.

Prerequisites

• SMTP AUTH and IMAP are enabled for the user in the Microsoft 365 admin center. See Microsoft 365: enable SMTP AUTH and IMAP for a user. If they are not, the connection will fail or replies will not be detected.
• You can sign in to the Microsoft account you want to connect.

Steps

1. Log in to your OutreachFox account.
2. Click Mailbox in the left-side menu.

1. Click Connect Mailbox.

1. Choose Office365 Outlook from the connection options.

1. Read the on-screen instructions. If the admin settings are not yet enabled, complete them now (link in the prerequisites), then come back to this screen.

1. Click Connect with Outlook.

1. Sign in with the Microsoft account and grant the requested permissions when prompted.

1. Click Accept to complete the connection.

1. The mailbox is now added and ready to use.

What you see afterwards

The mailbox appears in the Mailbox list with a connected status. Enable warmup, set a daily campaign limit and a signature, and it can be selected as a sender account in campaigns.

Tips

• Warm up for at least 14 days before sending campaigns. Microsoft mailboxes are generally more sensitive to sudden volume than Google; use the Microsoft warm-up profile.
• Keep 30–50 campaign emails per mailbox per day and 2–3 mailboxes per domain.
• If your organisation requires admin consent for third-party apps, an admin may need to accept the permissions once on behalf of the tenant; ask them to sign in at step 7.

Troubleshooting

• "Need admin approval" at sign-in — the tenant restricts user consent. A global admin must approve the OutreachFox app, or grant consent on behalf of the organisation at the same prompt.
• Connected but no replies detected — IMAP is disabled for the user. See Microsoft 365: enable SMTP AUTH and IMAP for a user.
• Sending fails with authentication error — SMTP AUTH is disabled for the user or blocked tenant-wide; see the same article.
• Mailbox disconnects after a while — see Fix mailbox disconnection errors (Google, Microsoft, SMTP).

Related articles

• Microsoft 365: enable SMTP AUTH and IMAP for a user
• Connect a Google Workspace mailbox to OutreachFox
• Connect any SMTP/IMAP mailbox (custom provider)
• Enable mailbox warmup
• Add a custom email signature to a mailbox
• Fix mailbox disconnection errors (Goog