Standard email setup for Microsoft 365 / Outlook

Connect your Microsoft 365 or Outlook email to Commslayer using the recommended Standard setup. This gives you unlimited sending with no daily caps.

Time required: About 10 minutes (standard) · 15–20 minutes (alias) · 30–60 minutes (multi-domain)

---

Standard setup (single inbox)#

Before you start#

You'll need:

• Admin access to your Microsoft 365 account
• Access to your domain's DNS settings (GoDaddy, Namecheap, Cloudflare, Shopify, etc.)
• An email address on your domain (like support@yourstore.com) with a mailbox you can forward from

Step 1: Create your inbox in Commslayer#

1. Go to Settings → Inboxes and click Add inbox
2. Select Email
3. Choose Standard setup (the recommended option)
4. Enter your support email address (e.g., support@yourstore.com)
5. Give your inbox a name (e.g., "Support" or your store name)
6. Click Create inbox

Step 2: Add DNS records#

Commslayer will show you two DNS records to add. These let us send emails on your behalf.

DKIM record (TXT)

1. Log in to your domain registrar
2. Add a new TXT record:
   • Name/Host: Copy from Commslayer (looks like xxxxxxxx._domainkey)
   • Value: Copy the long string from Commslayer
   • TTL: Leave as default
3. Save the record

Return-Path record (CNAME)

1. Add a new CNAME record:
   • Name/Host: Copy from Commslayer (looks like pm-bounces)
   • Value: Copy from Commslayer
   • TTL: Leave as default
2. Save the record

Click Verify in Commslayer. Records usually verify within minutes but can take up to 48 hours.

Tip: If verification fails, double-check that you copied the values exactly. Some registrars automatically append your domain — if so, remove it from the Name field.

Step 3: Enable external forwarding in Microsoft 365#

Microsoft 365 blocks external forwarding by default. You need to enable it before emails can reach Commslayer.

Enable external forwarding in Microsoft 365 →

Quick version:

1. Go to the Microsoft Defender Portal
2. Navigate to Email & collaboration → Policies & rules → Threat policies
3. Click Anti-spam outbound policy (Default) → Edit protection settings
4. Set Forwarding rules to On - Forwarding is enabled
5. Set Restriction placed on users who reach the message limit to No action, alert only
6. Save

Then set up email redirection in Outlook:

1. Sign in to Outlook on the web
2. Go to Settings → Mail → Rules
3. Create a new rule: Apply to all messages → Redirect to → paste the Commslayer forwarding address
4. Check Stop processing more rules
5. Save the rule

Step 4: Test your setup#

Send a test email to your support address from a different email account. It should appear in your Commslayer inbox within a minute or two. Only new forwarded emails will appear — historical emails are not imported.

---

Alias setup (single alias from a shared M365 inbox)#

Use this if you have multiple aliases (e.g., support@, info@, sales@yourstore.com) and want only one of them to go to Commslayer while the others stay in Outlook.

Steps 1–2: Create inbox and add DNS records#

Follow Steps 1 and 2 from the standard setup above, using your alias address (e.g., support@yourstore.com) as the inbox email.

Step 3: Create an Outlook rule for your alias#

Instead of enabling global forwarding, create a rule that targets only your support alias:

1. Sign in to outlook.office.com
2. Click the gear icon → View all Outlook settings
3. Go to Mail → Rules → Add new rule
4. Give the rule a name (e.g., "Forward support alias to Commslayer")
5. Under Add a condition, select To and enter your alias (e.g., support@yourstore.com)
6. Under Add an action, select Forward to and paste your Commslayer forwarding address
7. Optionally add a second action: Move to a separate folder so these emails don't clutter your inbox
8. Click Save

Note: If the alias is a shared mailbox (not a personal alias), set this up as a mail flow (transport) rule in the Exchange admin center under Mail flow → Rules instead.

Step 4: Test your setup#

Send a test email to your alias from an external account. It should appear in Commslayer. Emails to your other aliases will continue arriving in Outlook as usual.

---

Multi-domain setup (multiple domain aliases into one account)#

Use this if you have a single shared M365 mailbox with aliases across multiple domains (e.g., support@yourstore.com, support@yourstore.se, support@yourstore.de) and want all of them in Commslayer.

Why you need one inbox per domain: Each email carries the original recipient address in its headers. Commslayer uses that address to match the email to the right inbox. If only support@yourstore.com is registered, emails to support@yourstore.se won't appear.

Step 1: Create one Commslayer inbox per additional domain#

Repeat for every domain:

1. Go to Settings → Inboxes → Add inbox
2. Select Email → Standard setup
3. Enter the support address for that domain (e.g., support@yourstore.se)
4. Give the inbox a recognisable name (e.g., "Support – SE")
5. Click Create inbox and note the Commslayer forwarding address shown

Step 2: Add DNS records for each domain#

For each inbox, add the DKIM (TXT) and Return-Path (CNAME) records to that domain's DNS, exactly as in the standard setup above. Click Verify in Commslayer when done.

Step 3: Set up mail flow rules in Microsoft 365#

For each additional domain, create a mail flow rule in Exchange:

1. Sign in to the Microsoft 365 admin center
2. Go to Admin centers → Exchange → Mail flow → Rules
3. Click Add a rule → Create a new rule
4. Name the rule (e.g., "Forward support@yourstore.se to Commslayer")
5. Under Apply this rule if, select The recipient → address includes and enter the alias address
6. Under Do the following, select Redirect the message to and paste the Commslayer forwarding address for that inbox
7. Save, and repeat for each domain

Important: Use Redirect (not Forward). Redirect preserves the original To: header so Commslayer can match the email to the correct inbox.

Step 4: Test each inbox#

Send a test email to each alias from an external account. Each email should appear in its corresponding Commslayer inbox.

Managing multiple inboxes: Use labels or teams to organise by region or language, and automation rules to auto-assign conversations from each inbox to the right team.

---

Common issues#

"Your organization does not allow external forwarding" Follow the Enable external forwarding in Microsoft 365 → guide.

Emails not arriving

• Confirm the outbound spam filter policy was saved correctly
• Verify no conflicting rules exist in Outlook
• Confirm the forwarding/redirect address is copied fresh from Commslayer

DNS records not verifying

• Wait up to 48 hours and check whatsmydns.net
• If DNS is managed via M365 admin, update records under Settings → Domains → [your domain] → DNS records

Emails arriving in the wrong Commslayer inbox (multi-domain) Check that each mail flow rule's forwarding address matches the correct Commslayer inbox for that specific domain.

Emails to other aliases also going to Commslayer (alias setup) Review your rule — make sure the To condition specifies only your support alias, not a broader condition.

Need help?#

Contact us at karri@commslayer.com if you get stuck.