Checklist

Microsoft 365 Signature Setup Checklist

Deploy email signatures across your Microsoft 365 tenant using Exchange Online transport rules, Outlook client settings, and Entra ID integration for dynamic user data.

14 Steps

To complete M365 setup

40 min

Average configuration time

100%

Coverage across Outlook and OWA

What This Checklist Covers

Exchange Online Transport Rules

Use mail flow rules (transport rules) in Exchange Admin Center to append signatures server-side to all outgoing emails.

Entra ID Integration

Pull user attributes (name, title, department, phone) from Microsoft Entra ID to populate dynamic signature fields.

Outlook & OWA Deployment

Configure signatures that work across Outlook desktop, Outlook mobile, Outlook for Mac, and Outlook Web Access.

Microsoft 365 Setup Checklist

Log into the Exchange Admin Center (admin.exchange.microsoft.com) with Exchange Administrator or Global Admin credentials

Navigate to Mail flow > Rules and create a new transport rule for email signature injection

Set the rule condition to "Apply to messages sent to: Outside the organization" for external email signatures

Use the "Apply a disclaimer" action with "Append" to add your HTML signature template

Insert Active Directory attributes (%%DisplayName%%, %%Title%%, %%Department%%, %%PhoneNumber%%) for dynamic user data

Verify Entra ID (formerly Azure AD) user profiles have complete and accurate attribute data for all employees

Configure the fallback action to "Wrap" rather than "Ignore" so signatures are applied even when encryption is active

Create separate transport rules for different user groups using distribution lists or dynamic groups as conditions

Test the transport rule by sending emails from multiple users to external addresses and verifying signature content

Configure Outlook Web Access (OWA) signature settings in Exchange Admin Center under Settings > Mail > Compose and reply

Deploy Outlook desktop signatures via Group Policy or Microsoft Intune for managed devices

Disable user-level signature editing in Outlook if you want to enforce centralized signatures only

Test signature rendering in Outlook desktop (Windows), Outlook for Mac, Outlook mobile (iOS/Android), and OWA

Document transport rule configurations, Entra ID attribute mappings, and deployment scope for IT handoff

Microsoft 365 Signature Architecture

Directory Sync

Ensure Entra ID user profiles contain accurate name, title, department, and phone attributes. These fields populate your signature templates dynamically.

Transport Rule Setup

Create mail flow rules in Exchange Admin Center that append HTML signatures to outgoing emails, using AD attributes for personalization.

Client Configuration

Configure Outlook desktop via Group Policy or Intune, OWA via Exchange settings, and test across Outlook mobile apps.

Governance & Testing

Disable unauthorized user edits, test signatures from multiple users across all clients, and document the full configuration.

"Exchange transport rules seemed daunting at first, but this checklist broke it down into manageable steps. Our M365 signatures were live across 2,000 users within a day."

Michael Brennan

Cloud Infrastructure Lead, Sterling & Associates

Frequently Asked Questions

Can Exchange Online transport rules add per-user signatures?

Yes. Transport rules support Active Directory attribute placeholders like %%DisplayName%% and %%Title%%, which pull each user's data from Entra ID to create personalized signatures.

Do transport rule signatures appear in the Outlook compose window?

No. Transport rules apply signatures server-side after the email is sent, so users do not see the signature while composing. This can confuse users. Consider using a client-side tool alongside transport rules for compose-time preview.

How do I handle different signatures for internal vs. external emails?

Create two transport rules: one scoped to "messages sent outside the organization" with a full signature, and one for "messages sent inside the organization" with a simpler internal signature or no signature.

What happens if Entra ID attributes are missing for a user?

If an attribute placeholder (e.g., %%Title%%) is empty in Entra ID, the transport rule will insert a blank space. Clean up your directory data before deploying signatures to avoid empty fields.

Can I deploy signatures to Outlook mobile apps via transport rules?

Yes. Transport rules are applied server-side, so they work for all clients including Outlook mobile. However, Outlook mobile also has its own signature setting, which may duplicate the signature. Disable the Outlook mobile signature via Intune to prevent this.

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