Deploy Outlook signatures for users who do not log on to managed devices

2026-10-07

Client-based signature deployment assumes that every user regularly signs in to a managed Windows, macOS, or Linux device.

In many organizations, that is simply not the case: Frontline workers may use Microsoft 365 F licenses. Other users work exclusively in Outlook for the web or Outlook Mobile. Some share workstations, use personally owned devices, or access their mailbox from an unmanaged BYOD environment.

In these scenarios, relying on software that runs in the context of the logged-on user is not practical. There may be no primary managed device on which the software can run.

This is where SimulateAndDeploy comes in.

🔗Generate signatures centrally and push them into mailboxes

SimulateAndDeploy builds on the simulation capabilities of Set-OutlookSignatures. Instead of running Set-OutlookSignatures separately for every user on their device, an administrator runs the process centrally for multiple users.

The generated signatures and out-of-office replies are then pushed into the corresponding mailboxes through supported Outlook and Exchange mechanisms.

Instead of decentralized execution on user's devices in their security context, a service account on a central system is utilized.

SimulateAndDeploy is not part of the free Set-OutlookSignatures core. It is provided through the Benefactor Circle add-on, which supports the continued development of the open-source project.

🔗Designed for F-license, BYOD, and web-only scenarios

SimulateAndDeploy is particularly useful when users cannot or should not run Set-OutlookSignatures themselves. Typical scenarios include:

• Microsoft 365 F-license users
• Users working primarily with Outlook for the web
• Mobile-only users
• Unmanaged BYOD devices
• Shared workstations
• Users who do not regularly log on to a managed Windows, macOS, or Linux device
• Environments where software or configuration should not be distributed to every endpoint

Instead of depending on each user’s device, signature generation and deployment are handled by one or more centrally managed systems.

🔗SimulateAndDeploy versus client mode

Set-OutlookSignatures supports two complementary operating models.

🔗Client mode

In client mode, Set-OutlookSignatures runs in the security context of the logged-on user.

This is usually the preferred approach when users regularly sign in to managed devices. It uses resources that are already available on those devices and can run frequently, for example at logon or every few hours.

Client mode can also access local Outlook configuration that is not available from a central system.

🔗SimulateAndDeploy

SimulateAndDeploy runs centrally in the security context of a designated service account.

Users do not need a managed primary device, and Set-OutlookSignatures does not need to be deployed to every endpoint. Central execution also makes it easier to control software versions, configuration, templates, scheduling, and logging.

There are architectural tradeoffs to consider:

• One or more central execution systems are required.
• The central service account needs appropriate access to the target mailboxes.
• Mailbox access should follow least-privilege principles and can be granted temporarily where appropriate.
• Central runs are typically scheduled less frequently than execution on individual user devices.
• SimulateAndDeploy cannot inspect local Outlook configuration on users’ devices.
• Outlook for the web effectively becomes the "local Outlook" configuration available to the central process.

The two modes can also be combined. Client mode can be used for users with suitable managed devices, while SimulateAndDeploy covers users for whom client-side execution is unavailable or undesirable.

🔗Make signatures available across Outlook platforms

Signature generation and signature delivery are separate stages.

In the first stage, Set-OutlookSignatures transforms centrally managed templates into personalized signatures and out-of-office replies. It can enrich the templates with information from sources such as Microsoft Entra ID, Active Directory, Exchange, or other configured data sources.

In the second stage, the finished signatures are made available through one or more supported delivery channels.

Depending on the environment and configuration, these channels can include:

• Outlook for the web signatures
• Microsoft roaming signatures in Exchange Online
• The Set-OutlookSignatures Outlook add-in
• A signature collection stored in a draft email
• Export to a document folder, such as a OneDrive-synchronized location

The Outlook add-in can complement SimulateAndDeploy, especially for mobile and unmanaged BYOD scenarios. It can select signatures based on the sending mailbox and configured rules without requiring the full Set-OutlookSignatures process to run on the endpoint.

🔗No message rerouting or transport-level stamping

SimulateAndDeploy does not reroute email, intercept messages, or add signatures while messages pass through the mail transport system.

It creates signatures centrally and makes them available through supported mailbox- and Outlook-based delivery channels.

This allows users to see and work with their signatures while composing an email, rather than having an unseen transport service modify the message after it has been sent.

🔗Go beyond mailboxes connected in Outlook

Central deployment becomes even more powerful when SimulateAndDeploy is combined with the VirtualMailboxConfigFile parameter.

Normally, signature processing begins with the mailboxes that Outlook can identify for a user. However, users may be allowed to send from additional Exchange recipient objects that are not configured as full mailboxes in Outlook.

Examples include:

• Shared mailboxes
• Mailboxes for which a user has Send As permission
• Mailboxes for which a user has Send on Behalf permission
• Delegated sender identities
• Distribution groups from which a user is allowed to send
• Temporary holiday or sickness-cover mailboxes

VirtualMailboxConfigFile describes these additional relationships. Set-OutlookSignatures can then create signatures for identities a user is authorized to act as, even if the corresponding mailbox or recipient object has not been added to the user’s Outlook profile.

The parameter does not grant Exchange permissions. It tells Set-OutlookSignatures which already-authorized sender relationships should be considered during signature processing.

The combination of Export-RecipientPermissions, VirtualMailboxConfigFile, and SimulateAndDeploy automates this process.

Export-RecipientPermissions collects the relevant Exchange recipient permissions and documents which users may act as which recipient objects. Set-OutlookSignatures can use this information through VirtualMailboxConfigFile.

The resulting workflow is straightforward:

1. Export-RecipientPermissions reads the relevant Exchange permissions.
2. The exported information describes the authorized user-to-recipient relationships.
3. Set-OutlookSignatures consumes this information through VirtualMailboxConfigFile.
4. SimulateAndDeploy generates the required signatures centrally.
5. The signatures are deployed to the corresponding users’ mailboxes.
6. When permissions are removed and the export is refreshed, obsolete signatures can also be removed.

Exchange permissions remain the source of truth. There is no need to maintain a separate static list of every user, shared mailbox, delegate, and temporary replacement.

This is particularly valuable in dynamic environments where Send As and Send on Behalf permissions change frequently.

🔗A centralized deployment option, not a replacement for every client deployment

SimulateAndDeploy is not universally better than client mode.

Client mode remains a strong choice when users regularly log on to managed devices and Set-OutlookSignatures can run in their own security context. It can run more frequently and has access to local Outlook state.

SimulateAndDeploy is the better architectural choice when endpoint-based execution is unavailable, unreliable, or unwanted.

Organizations can use either mode or combine both:

• Use client mode for users with managed primary devices.
• Use SimulateAndDeploy for F-license, web-only, mobile-only, shared-device, and unmanaged BYOD users.
• Add VirtualMailboxConfigFile for sender identities that are not connected as full Outlook mailboxes.
• Generate the virtual mailbox configuration with Export-RecipientPermissions when Exchange permissions should be the source of truth.
• Add the Outlook add-in where context-aware signature selection is needed across Outlook platforms.

The result is centralized signature management without assuming that every user owns, manages, or regularly logs on to a traditional corporate endpoint.

🔗Set-OutlookSignatures centralizes email signatures and out-of-office replies across every Outlook platform

Consistent branding for Marketing, centralized control for IT, and zero manual effort for employees. Sovereign by design, it keeps data within systems you already trust.

⚡ 3-Step Quickstart	🎯 Book Interactive Demo	🔍 Website
For IT Administrators and Technical Evaluation. No Signup Required.	For Executives and Decision-Makers from IT, Marketing, and Security.	Features, architecture, documentation, and downloads.