Comparing Outlook Add-in deployment methods

Overview

The Opensense Outlook Add-in supports three deployment methods: Stamping, Plain Text Block, and Visual Preview. Each method determines how and where signatures are applied. Each makes different tradeoffs across compliance control, compose visibility, analytics depth, and banner targeting. Choose the right method before you configure the add-in, to save significant rework.

Quick decision guide

• Server-side, after send Stamping

  Choose it if compliance and full server-side control are the priority, and you don't need the signature visible while composing.

• Recommended Plain Text Block

  Choose it if you need both server-side compliance control and a signature preview while composing. This is the recommended method for most deployments.

• Client-side, in compose Visual Preview

  Choose it if users need to see and interact with their signature before sending, or if your organization sends encrypted emails that can't be processed server-side.

Comparison table

Capability	Stamping	Plain Text Block	Visual Preview
Signature applied	Server-side, after send	Server-side, after send	Client-side, in compose
Compose visibility	None. The add-in pane shows a preview of the recipient's signature.	A token in compose. The add-in pane shows a preview of the recipient's signature.	The full rendered signature in the compose window
User can edit the signature before sending	No	No	Yes
Compliance enforcement	Full	Full	Not enforced. User edits bypass Opensense.
Banner targeting	Recipient-based	Recipient-based	Sender-based only
Analytics	Advanced (views, clicks, video replays)	Advanced (views, clicks, video replays)	Basic (views and clicks only)
Encrypted email support	No	No	Yes
Mail flow rule required	Yes	Yes	Optional (the rule handles unsigned emails)
Custom Compose Fields	Not compatible	Compatible	Compatible
Mobile From switching	Not supported by any method (a Microsoft limitation)
Best for	Organizations that prioritize governance, with no compose visibility requirement	Organizations that need compliance control, with employee signature awareness	Organizations that prioritize the compose experience, or send encrypted email

Stamping

Stamping removes any locally drafted signature from the outbound email, and applies the full HTML signature server-side after the message is sent. Nothing is inserted into the compose window. Users can open the add-in pane to see a preview of the signature recipients will receive. Because Opensense’s servers apply the signature, the sender can’t change it.

Best for

Organizations where compliance and legal disclaimer enforcement take priority, and a signature in the compose window is not required.

Strengths

• Full compliance enforcement: signature content is always controlled centrally
• Recipient-based banner targeting and advanced analytics
• No changes to the compose window for users
• The add-in pane preview confirms what recipients will see

Limitations

• No signature in the compose window. Users see the preview only when they open the add-in pane.
• Not compatible with Custom Compose Fields
• Can't apply signatures to encrypted outbound email

For edge cases, see Expected behaviors in routed Outlook Add-in deployments.

Plain Text Block

The Plain Text Block method inserts a [[#]] token into the compose window, and the add-in pane shows a non-clickable preview of what recipients will see. The mail flow rule detects the token, routes the email to Opensense, and applies the full HTML signature server-side. The preview confirms that a signature will be applied, without letting users edit it.

This is Opensense’s patented approach, and the recommended method for most deployments.

Best for

Organizations that need server-side compliance control, and want employees to have signature awareness through the add-in pane. This method bridges the gap between Stamping and Visual Preview.

Strengths

• Full compliance enforcement: the signature is applied and controlled server-side
• The add-in pane preview shows users exactly what recipients will receive
• Recipient-based banner targeting and advanced analytics
• Compatible with Custom Compose Fields

Limitations

• A mail flow rule is always required
• Can't apply signatures to encrypted outbound email
• The preview is in the add-in pane only. The compose window shows only the token.

For edge cases, see Expected behaviors in routed Outlook Add-in deployments.

Visual Preview

Visual Preview renders the full HTML signature client-side in the compose window. Users can see the signature and edit it manually before sending. Emails sent with a manually edited signature bypass Opensense’s servers, so those changes are not tracked, blocked, or enforced.

Best for

Organizations where the compose experience takes priority over strict governance, or with encrypted email workflows where server-side processing is not possible.

Strengths

• Full compose visibility: users see the rendered signature as it will appear to recipients
• The only method that supports encrypted outbound email (sensitivity labels)
• Compatible with Custom Compose Fields

Limitations

• Users can edit the signature before sending, so compliance can't be enforced
• Banner targeting is sender-based only, with no recipient-based targeting
• Analytics are basic (views and clicks), with no advanced analytics or video replays

For details, see Outlook Add-in Visual Preview capabilities and tradeoffs.

Making your decision

The right method depends on how your organization weighs compliance control against the compose experience, and whether advanced marketing capabilities are a priority. Most organizations with active governance or legal requirements should default to Plain Text Block: it delivers server-side control with the compose visibility that Stamping lacks. Visual Preview is the correct choice when encrypted email is in scope, or when your organization’s culture requires employees to see and own their signature before sending.

Find your situation in each factor to narrow down the right method.

Compliance requirements

• Legal disclaimers or brand standards must be enforced on every email, without exceptionStamping or Plain Text Block, the only viable options

Marketing and analytics

• Recipient-based banner targeting and advanced analyticsA server-side method: Stamping or Plain Text Block
• Sender-based targetingVisual Preview supports this only

Encrypted email

• Microsoft sensitivity labels, or other encryption that processes before mail flow rules evaluateVisual Preview, the only method that will apply a signature

User experience

• Employees need to see their signature before sending, for example, to verify personalized fieldsPlain Text Block, which gives that awareness without sacrificing compliance control

You can combine methods. Some organizations use Visual Preview for encrypted email workflows, and Plain Text Block for standard outbound email. Contact help@opensense.com if you need guidance on a hybrid configuration.

Still unsure which method fits?

Reach out to your Opensense account manager or help@opensense.com. They can walk through your compliance and marketing requirements, and recommend a configuration.

What’s next

• Outlook Add-in overview
• Outlook Add-in supported environments
• Configuring the Outlook Add-in in Domain Settings