Outreach

Outreach connects each person's Microsoft 365 mailbox with Microsoft Graph and sends their email through it, and Footer365 signs mail that passes through your Microsoft 365. Choose how your CRM or app sends its mail explains the two ways to send, and this guide follows the first.

At a glance

• Can be signed: email Outreach sends on a person's behalf through their connected mailbox. Outreach says Mail.Send is used to send emails on the person's behalf, and that "Outreach can schedule automated emails while the user is not logged into Outreach."
• Cannot be signed: anything Outreach does not send through the mailbox. The page read does not describe such email, so check one message of each kind.
• How it connects: Outreach says "Microsoft Graph is a more modern substitute for EWS (Exchange Web Services) API", and offers Office 365 OAuth (recommended) as the email provider.
• Status: from Outreach's documentation as read on 23 October 2026, not tested by Footer365. The page shows "Modified on Fri, 11 Sep" and no year.

Before you start

• Footer365 mail flow is set up. With the Outlook add-in only, no mail Outreach sends is signed. Using the Outlook add-in only
• Every person who sends from Outreach has a Footer365 signature rule that covers them.
• Your Microsoft 365 or Azure administrator may need to approve Outreach, as in step 1.

Step 1: Approve the app in Microsoft 365

Outreach asks for these Microsoft permissions, and says what each is for:

Outreach says that if your tenant requires approval, people see a "Need admin approval" page and cannot go on, and that administrators can approve in the Azure admin centre or start the admin consent flow, or grant consent for the whole tenant so individual people do not need to. Approve an app's access in Microsoft 365

Step 2: Choose the mailbox

• Each person's own mailbox is what Outreach connects. The mail is signed with the signature your rules give that person.
• Aliases: Outreach says customers "who use multiple email aliases and UPN names can connect mailboxes to Outreach in a seamless way", and that when a person has several aliases, only the mailbox in active use should have Syncing and Sending turned on.
• A shared mailbox: Outreach's page does not address it. Do not assume it works.

Step 3: Connect it in Outreach

Following Outreach's steps, for a single mailbox:

1. Go to Settings > You > Mailboxes.
2. Select Edit, or Set up account, on the default mailbox.
3. In the Email Provider drop-down, choose Office 365 OAuth (recommended).
4. Select Connect with Office 365.
5. Accept Microsoft's consent prompt, and select Request approval if administrator consent is required.
6. Wait for the mailbox to show Connected, turn on the Syncing and Sending toggles, and save.

Outreach's own steps: How to connect Office 365 mailbox to Outreach using Microsoft Graph.

Step 4: Check one message

1. Send an email from Outreach to an address outside your organisation that you can read.
2. Open the headers of the copy you receive.
3. Return-Path should be the sender's own address, and X-Footer365-Relay-Id should be there.
4. Look in the sender's Sent Items. Outreach's page does not say whether the message is saved there.

Check a sequence email as well, because Outreach sends those while the person is not signed in. What other results mean: Mail from our CRM is not signed.

Where the signature goes

Outreach says it uses MailboxSettings.Read "to get user signature and timezone". Check whether its messages carry the person's own signature as well as Footer365's. If you see two signatures, remove the one in the person's mailbox settings, or in Outreach. To place Footer365's signature in a template, use a marker, and check one message, because Outreach's page does not say what it does with text in double braces. Place the signature with a marker

What is not signed

Outreach's page read does not describe email that Outreach sends from its own servers. Check one message of each kind you send, and treat any message without X-Footer365-Relay-Id as unsigned.

What stops working

Outreach says Microsoft Graph "is a more modern substitute for EWS". Microsoft starts switching Exchange Web Services off in October 2026 and finishes in April 2027, so if a mailbox was connected with Outreach's EWS option, reconnect it with Office 365 OAuth (recommended). The page read does not describe the EWS option or its steps. Exchange Web Services is being switched off

Limits

Outreach's page states no sending limit. Microsoft's limits for a mailbox apply: 10,000 recipients a day and 30 messages a minute. Microsoft: Exchange Online limits

Last resort: a connector to Exchange Online

Outreach's page describes no connector from Outreach into Exchange Online, and Outreach runs on its own servers. Microsoft says SMTP relay cannot be used for a service hosted by someone else, and asks such a service for a certificate of your own. So there is no connector route for Outreach mail. Last resort: a connector to Exchange Online

If it does not work

1. A person sees "Need admin approval". Outreach says calendar syncing also stops until approval. Approve an app's access in Microsoft 365
2. The mailbox does not show Connected. Reconnect with Connect with Office 365.
3. The message has no X-Footer365-Relay-Id. It did not pass through Microsoft 365.
4. It passed through Footer365 but is unsigned. The signature was not added
5. Still not clear. Mail from our CRM is not signed

Sources

Read on 23 October 2026:

• Outreach: How to connect Office 365 mailbox to Outreach using Microsoft Graph, "Modified on Fri, 11 Sep", year not shown.