What it does

Four things the integration does for you.

OAuth via Microsoft 365 or Outlook.com

Sign in once with your Microsoft work or personal account; no app passwords, no SMTP credentials stored. The integration uses Microsoft's Graph API with the minimum scopes needed (Mail.Send, Mail.Read, Mail.ReadWrite).

Send from your Outlook mailbox in your voice

Outbound goes through your actual Outlook / Microsoft 365 account — appears in your Sent folder, threads correctly with replies, no look-alike domain. Brand-voice extraction reads your sent folder on connect.

Reply detection via Graph API

Microsoft Graph subscriptions or polling pick up replies on threads Overwise sent. Replies auto-classify (positive / question / negative / OOO) and surface in the AI Inbox. Outbound auto-stops on reply.

Group / shared-mailbox support

Personal mailboxes are the default, but Microsoft 365 group mailboxes are supported on Growth and Founder Team plans (Send-As permission required). Useful for founder-led outbound from [email protected].

Setup

How to connect, in 60 seconds.

  1. 01

    Click 'Connect mailbox' in your project settings

    From Settings → Mailboxes, hit 'Connect Outlook'. You'll be sent to Microsoft's consent screen.

  2. 02

    Authorize Mail.Send + Mail.ReadWrite scopes

    Microsoft asks you to approve the requested scopes. These are the minimum needed to send under your name, read replies on Overwise-sent threads, and apply auto-labels. No other scopes requested.

  3. 03

    Brand-voice extraction runs in the background

    On first connect, Overwise reads recent sent-folder messages via Graph API and synthesizes a voice fingerprint. Takes ~90 seconds. You can edit or remove the extracted samples anytime.

  4. 04

    DNS validation runs at first send

    Before the first outbound, Overwise verifies your domain has SPF, DKIM, and DMARC records aligned with Microsoft 365's sending IPs. If any check fails, sending is blocked until you fix the record. The DNS check page tells you exactly what to add.

Security note

Overwise stores only the Microsoft OAuth refresh token, encrypted at rest with AES-256. We never store your password or any plaintext message body beyond the in-flight draft. Revoke from your Microsoft account → Privacy → Apps and services any time. The Graph API permissions list is auditable at https://account.microsoft.com/privacy.

Outlook-integration questions, answered short.

Microsoft 365, Outlook.com, or both?

Both work. Microsoft 365 ([email protected]) is recommended for outbound at any scale — Outlook.com / Hotmail addresses are deprioritized by ESP filters for cold outreach. The same OAuth flow handles both — just sign in with the appropriate account.

Will my Outlook get marked as spam?

Not if your DNS is healthy. Overwise blocks sending if SPF / DKIM / DMARC checks fail at first send. The 14-day warmup ramp (10 → 25 → 50 → 100/day) is non-overridable for new mailboxes. Bounce-rate auto-pause kicks in at 8% mailbox-wide. These guardrails are the deliverability moat.

Can I send from a shared / group mailbox?

Yes, on Growth and Founder Team plans. The signing-in user must have Send-As permission on the group mailbox (configured in Microsoft 365 admin). The 'From' header will be the group address; reply detection still works because the group inbox receives all replies.

Does the integration work with Exchange on-premise?

No — only Microsoft 365 / Outlook.com via the cloud Graph API are supported. Self-hosted Exchange Server isn't on the roadmap because the auth + send surface is different and rarer for the founder-buyer we serve.

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