How signatures are added to emails sent as / on behalf of other users

Sometimes, a user or a group of users has permission to send messages as other users or on their behalf. These users are referred to as delegates. See the examples below to learn how CodeTwo Email Signatures 365 works for users with delegate permissions.

Example 1: using the Send As permission in the cloud (server-side) mode

You use CodeTwo in cloud (server-side) mode. User A is assigned the Send As permission to User B's mailbox.

When User A sends an email and enters User B's email address in the From field, the message will be considered as sent by User B. As a result, the rules for User B will apply (and User B's signature will be added). The Sent Items Update (SIU) service will update the message in User B's Sent Items folder.

In combo mode, only emails routed through the CodeTwo cloud service will be processed as presented in this example.

Example 2: using the Send On Behalf Of permission in the cloud (server-side) mode

You use CodeTwo in cloud (server-side) mode. User A is assigned the Send On Behalf Of permission to User B's mailbox.

When User A sends an email and enters User B's email address in the From field, the message will be considered as coming from User A. As a result, the rules for User A will apply (and User's A signature will be added). The SIU service will update the message in User A's Sent Items folder.

In combo mode, only emails routed through the CodeTwo cloud service will be processed as presented in this example.

Example 3: using the Send As or Send On Behalf permission in the Outlook (client-side) mode

You use CodeTwo in Outlook (client-side) mode. User A is assigned either the Send As or Send On Behalf permission to User B's mailbox.

When User A composes an email, CodeTwo’s Outlook add-in automatically adds a signature. However, if User A changes the sender in the From field to User B, the signature is removed from the email, and the add-in pane shows the signatures configured for User B. User A can now manually add the correct signature to an email. Learn more

In combo mode, this example applies only to emails that receive CodeTwo Outlook signatures.

If you want to know more, see our Knowledge Base article for examples with screenshots.

Sent Items Update - additional information

In order for the Sent Items Update feature to work as described above, you need to enable message copying in your Exchange Online, as described in this Microsoft blog article.

If you use the Open another mailbox option (Fig. 1.) in Outlook on the web (OWA) to access another mailbox and send an email on behalf of it, Exchange Online won’t copy that email to your mailbox, preventing the SIU service from updating the email with an email signature.

Fig. 1. Accessing another mailbox in OWA.