---
title: "Send as vs Send on Behalf"
slug: "send-as-vs-send-on-behalf"
tags: ["Microsoft 365"]
updated: 2025-05-06T00:40:22Z
published: 2025-05-06T00:40:22Z
canonical: "help.opensense.com/send-as-vs-send-on-behalf"
excludeFromExternalSearch: true
---

> ## Documentation Index
> Fetch the complete documentation index at: https://help.opensense.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Send as vs Send on Behalf

## Understanding "Send As" and "Send on Behalf" in Outlook

This guide explains the **"Send As"** and **"Send on Behalf"** permissions in Outlook and how they work with Opensense email signatures. It includes details on configuration and usage.

Note

This applies only to **routed** solutions using the **plain text block** or **stamping**, not to those with full visual preview.

### 1. "Send As" Permission

#### Overview

The **Send As** permission allows a delegate to send an email as though it was sent directly by the mailbox owner. The email appears to recipients as if it were sent by the owner without any indication of delegation.

#### Example

Jack has been granted **Send As** permission for Susie’s mailbox. When Jack sends an email using **Send As**, the email appears to be sent by Susie, and Susie’s signature is used in the email.

#### Configuration in Opensense

To ensure proper signature application for **Send As** emails, follow these steps:

1. Navigate to **Domain Settings** in Opensense.
2. Enable the option **"Use email body From: header"**.

Additional Information

This setting ensures Opensense identifies the correct user (for example, Susie) based on the From field in the email body, so the appropriate signature is applied.

### 2. "Send on Behalf" Permission

#### Overview

The **Send on Behalf** permission allows a delegate to send emails on behalf of the mailbox owner. In this case, the **From** line indicates that the email was sent by the delegate on behalf of the owner.

#### Example

Jack has been granted **Send on Behalf** permission for Susie’s mailbox. When Jack sends an email using this permission, the **From** line displays: *"Jack on behalf of Susie."*

#### Notes for Opensense Integration

Emails sent **"on behalf of"** the mailbox owner will reflect the delegate’s identity in the email headers, which may affect the signature application process. Be sure to test and verify that Opensense correctly applies the intended signature.

### 3. Envelope Sender vs. From Header

Understanding the distinction between the **Envelope Sender** (SMTP From) and the **From** header is crucial when configuring email signatures:

#### Envelope Sender (SMTP From)

The Envelope Sender is the actual sender of the email at the transport level. It is used during the SMTP transaction for routing and delivery. You can see it in the email header as `smtp.mailfrom=email.com`.

#### From Header

The From header defines who the recipient perceives as the sender. This can include more visible details, such as *"Jack on behalf of Susie"* in **Send on Behalf** scenarios or simply Susie’s name in **Send As** cases.

### 4. Example Scenarios

#### Scenario 1: Jack Sends As Susie

- **Envelope Sender (SMTP From):** Susie@company.com
- **From Header (Visible to Recipient):** Susie@company.com

Since Jack has **Send As** permission, both the Envelope Sender and the From field reflect Susie’s email address, making it appear that Susie sent the email directly.

#### Scenario 2: Jack Sends On Behalf of Susie

- **Envelope Sender (SMTP From):** Jack@company.com
- **From Header (Visible to Recipient):** Jack on behalf of Susie

In the **Send on Behalf** scenario, the Envelope Sender shows Jack’s identity, while the From header clearly indicates that the email is sent on behalf of Susie.

### 5. Summary of Envelope Sender and From Header

| Scenario | Envelope Sender (SMTP From) | From Header (Visible to Recipient) |
| --- | --- | --- |
| **Jack sends As Susie** | Susie@company.com | Susie@company.com |
| **Jack sends On Behalf of Susie** | Jack@company.com | Jack on behalf of Susie |

---

### 6. Differences Between "Send As" and "Send on Behalf"

| Feature | "Send As" | "Send on Behalf" |
| --- | --- | --- |
| **Email Appearance** | Sent directly from the mailbox owner (no mention of the delegate). | Indicates that the delegate sent the email on behalf of the mailbox owner. |
| **Use Case** | Used when the email must appear as if sent solely by the owner. | Used when transparency about delegation is required. |
| **Envelope Sender** | Uses the owner’s email address (SMTP From). | Uses the delegate’s email address (SMTP From). |
| **From Header** | Appears as the owner’s email address. | Appears as “Delegate on behalf of Owner.” |

### Additional Resources

For more details on configuring these permissions in Outlook, see the following resources:

- [Microsoft Support: Allow a Delegate to Manage Your Mail and Calendar](https://support.microsoft.com/en-us/office/allow-someone-else-to-manage-your-mail-and-calendar-5326c653-0721-4ec4-b9b2-1e30d18f4aa8)
- [Send As vs Send on Behalf vs Full Access](https://office365concepts.com/send-as-vs-send-on-behalf-vs-full-access/)

### Opensense Support

For further assistance, contact Opensense Support:

- Email: help@opensense.com
- Knowledge Base: help.opensense.com