Setting up Email Auto Forwarding (Outlook/Microsoft)

Auto-forwarding sends your client's emails to Briefcase automatically. Briefcase picks out the individual transactions and puts them into your client's Briefcase inbox, handling duplicate checks and multi-page invoice splits along the way.

There are two ways to set this up:

• Forward everything → you have direct access to the client's inbox and want all of its email forwarded to Briefcase.

• Forward specific senders → you receive emails from several clients in one shared inbox and want each client's emails forwarded to their own Briefcase account.

You'll find the client's Briefcase forwarding address (ending in @briefcase.to) in the client's Business Settings in Briefcase.

Option A: Forward everything

Outlook for Windows

1. On the Home tab, click Manage Rules & Alerts, then New Rule.

2. Under "Start from a blank rule", select Apply rule on messages I receive and click Next.

3. Leave the conditions empty and click Next, then click Yes to apply the rule to every message.

4. Select forward it to people or public group, click the underlined people or public group, enter the client's Briefcase forwarding address, and click OK.

5. Click Next past the exceptions (leave them empty), then click Finish.

6. Name the rule (e.g. [Client Name] - Briefcase Auto Forwarding) and click OK.

Outlook for Mac

1. On the Message tab, click Rules, then Edit Rules.

2. Click + to add a rule and name it (e.g. [Client Name] - Briefcase Auto Forwarding).

3. Set the condition to Apply to all messages.

4. Set the action to Forward to and enter the client's Briefcase forwarding address.

5. Click Save.

All emails received in this inbox will now be forwarded to your client's Briefcase inbox.

Option B: Forward specific senders (multiple clients)

Create one rule per client that matches that client's sender addresses.

Outlook for Windows

1. On the Home tab, click Manage Rules & Alerts, then New Rule.

2. Select Apply rule on messages I receive and click Next.

3. Tick the condition from people or public group, click the underlined from people or public group, and enter the sender addresses belonging to one client. Click Next.

4. Select forward it to people or public group, click the underlined people or public group, enter that client's Briefcase forwarding address, and click OK.

5. Click Next past the exceptions (leave them empty), then click Finish.

6. Name the rule (e.g. [Client Name] - Briefcase Auto Forwarding) and click OK.

7. Repeat for each client.

Outlook for Mac

1. On the Message tab, click Rules, then Edit Rules.

2. Click + to add a rule and name it (e.g. [Client Name] - Briefcase Auto Forwarding).

3. Set the condition to From and enter that client's sender addresses (e.g. admin@, invoices@, finance@).

4. Set the action to Forward to and enter that client's Briefcase forwarding address.

5. Click Save.

6. Repeat for each client.

Emails will now be forwarded to each client's Briefcase inbox based on your rules.

Troubleshooting: "Your organization doesn't allow external forwarding"

If Outlook shows "Your organization doesn't allow external forwarding. Please contact your administrator for further assistance" when your rule tries to forward, the block is coming from Microsoft 365 — not from Briefcase. Since 2020, Microsoft blocks automatic external forwarding by default through its outbound anti-spam policy, so a Microsoft 365 administrator needs to allow forwarding to Briefcase.

Step 1 — Allow automatic forwarding for the mailbox

We recommend scoping this to only the mailbox(es) that forward into Briefcase, so the rest of your organisation stays locked down.

1. Go to the Microsoft Defender portal (security.microsoft.com).

2. Open Email & collaboration → Policies & rules → Threat policies → Anti-spam.

3. Click Create policy → Outbound.

4. Give it a name (e.g. Allow Briefcase forwarding) and, under Users, groups, and domains, scope it to the mailbox(es) that forward into Briefcase.

5. Under the protection settings, set Automatic forwarding rules to On – Forwarding is enabled.

6. Click Save. Changes can take up to an hour to take effect.

Step 2 (optional) — Restrict forwarding to Briefcase only

Step 1 lets those mailboxes forward anywhere. To allow forwarding only to Briefcase and keep every other external destination blocked, add a mail flow rule:

1. Go to the Exchange admin center (admin.exchange.microsoft.com) → Mail flow → Rules → Add a rule → Create a new rule.

2. Under Apply this rule if, choose The message properties → include the message type → Auto-forward.

3. Add an exception: Except if → The recipient → address matches any of these words, and enter briefcase.to.

4. Under Do the following, choose Block the message → reject the message and include an explanation.

5. Click Save.

The result: auto-forwards to @briefcase.to are allowed, and auto-forwards to any other address stay blocked. Every Briefcase forwarding address ends in @briefcase.to (for example acme-limited-4821@briefcase.to), so allowing that one domain is all you need.

If the block persists after these changes, ask your admin to check for a custom mail flow (transport) rule that blocks external forwarding, under Exchange admin center → Mail flow → Rules.

Good to know

• Send a test email after setup to confirm forwarding is working.

• If you see "Your organization doesn't allow external forwarding", follow the Troubleshooting section above. If you don't see the rule options at all, contact your IT support.

• Using Gmail instead? See Setting up Email Auto Forwarding (Gmail).

• Using an email client other than Outlook or Gmail? Email us at support@briefcase.so and we'll help you get set up.