How to add signatures to emails sent from shared/group mailboxes

Learn how to configure CodeTwo Email Signatures for Office 365 to add signatures to emails sent from shared mailboxes (server-side and client-side mode) and group mailboxes (client-side mode only).

Shared mailboxes are often used to collect incoming emails in a single mailbox, playing the role of a single point of contact for people from outside your organization. These emails can be later answered by one of the designated users responsible for handling high-load communication routes, i.e. email addresses such as [email protected], [email protected], [email protected], etc.

Groups in Microsoft 365 are more collaboration-focused, allowing their members to access services such as SharePoint or Planner. Members from inside or outside your organization (if enabled by an admin) can also use the common group mailbox to send emails.

How to configure the program for this scenario

Use the links below to learn how to:

• Set up users' permissions to a shared mailbox in Microsoft 365 (Office 365)
• Send emails as or on behalf of a shared or group mailbox
• Set up server-side signatures for shared mailboxes
• Set up client-side signatures for shared mailboxes and group mailboxes

Set up user's permissions to a shared mailbox in Microsoft 365 (Office 365)

If you do not yet have a shared mailbox, create it in the Microsoft 365 admin center by following these instructions.

To configure permissions to a shared mailbox, open your Microsoft 365 admin center. Then go to Teams & groups > Shared mailboxes and select a shared mailbox from the list (Fig. 1.). In the Manage mailbox permissions section, click the type of permissions you want to edit (Fig. 1., item 3).

Fig. 1. Accessing shared mailbox permissions in the Microsoft 365 admin center.

Click Add permissions (Fig. 2., item A) and select users that will be allowed to send emails as or on behalf of this shared mailbox, depending on which type of permissions you clicked in the previous step. Confirm by clicking Add. You can remove permissions by selecting a user and choosing Remove permissions (Fig. 2., item B).

Fig. 2. Adding (A) or removing (B) users' permission to a shared mailbox.

How to send emails as or on behalf of a shared or group mailbox

When composing an email in Outlook desktop or OWA, click the From field to expand a drop-down list. Select the desired mailbox if it is already on the list (Fig. 3.).

Fig. 3. Selecting a different mailbox as an email sender.

If your mailbox is not on the list, click Other Email Address and type the email address of the mailbox. In your Outlook desktop app, you can also click From to open the Global Address List from where you can select your shared or group mailbox (Fig. 4.). Click OK to confirm and close.

Fig. 4. Selecting a shared mailbox from the Global Address List.

If the From field is not displayed in the email compose window:

• In Outlook desktop, go to the Options tab and click the From button on the ribbon (Fig. 5.).
• In Outlook on the web (OWA), click the ellipsis (three dots) button at the top of the email compose window and choose Show From (Fig. 5.).

Fig. 5. Displaying the From field in Outlook desktop (left) and OWA (right).

How to set up server-side signatures for shared mailboxes

In server-side mode, the way signatures are added to emails sent from a shared mailbox depends on users' permissions set for this mailbox:

• Emails sent by users with the Send as permission will receive a signature configured for the shared mailbox itself. Note that this signature will not contain personalized user's information, e.g. their first name, last name or position.
• Emails sent by users with the Send on behalf permission will receive a personalized signature, configured for these users.

Use the links below to learn how to:

• Create a signature rule for use with the Send as permission
• Create a signature rule for use with the Send on behalf permission

Create a signature rule for use with the Send as permission

First, you need to create a signature rule that will add an email signature to messages sent from a shared mailbox. To do this, go to app.codetwo.com, create a new server-side signature rule and name it accordingly, e.g. Shared mailbox for orders (Fig. 6.).

Fig. 6. Creating a new server-side signature rule.

Next, go to the Senders step. Click Add > Selected senders. In the Select users window, find your shared mailbox (e.g. [email protected]) on the list, select it and confirm by clicking OK (Fig. 7.).

Fig. 7. Selecting a shared mailbox as a sender.

Configure the other rule conditions and options and prepare a signature template to best suit your needs.

When your signature rule is ready, make sure to apply your changes by clicking the Save & Publish button.

Create a signature rule for use with the Send on behalf permission

If your users have the Send on behalf permission to a shared mailbox, you need to create a signature rule that adds a personalized signature to all emails sent by these users. This can be either:

• a standard email signature for all employees already in use in your organization

or

• an email signature designed specifically for the shared mailbox users.

In the case of an existing standard signature, you do not need to make any additional changes to your server-side rules. The program will automatically add a signature when an email is sent from a shared mailbox.

If you would like to design a special signature template for the shared mailbox users, read this article on creating signatures for specific senders within a Microsoft 365 organization. Note that this signature will be used in all emails sent by the shared mailbox users, not only in those that are sent on behalf of the shared mailbox.

How to set up client-side signatures for shared mailboxes and groups

In client-side mode, the configuration differs between shared mailboxes and group mailboxes. For specific instructions, click a link below:

• Shared mailboxes
• Groups (Microsoft 365 group mailboxes, distribution lists and mail-enabled security groups)

Create a client-side signature rule for a shared mailbox

Client-side signatures can be manually added to emails sent on behalf or sent as a shared mailbox.

You can create a new rule that will be used to add a separate signature template for a shared mailbox or make use of an existing signature rule (and email signature). Either way, go to app.codetwo.com, select the rule you want to edit and go the Senders step. Add the shared mailbox by clicking Add > Selected senders (below the top list) and choosing it in the picker. A sample configuration is shown in Fig. 9.

Fig. 9. A shared mailbox added to the senders list of your client-side signature rule.

Go to the Design step and edit or create a signature template that will be added to emails sent from your shared mailbox. 

Finally, configure the remaining options according to your needs and click Save & Publish for the changes to take effect.

Create a signature rule for a group mailbox

In the case of groups, client-side signatures can be manually added to emails sent on behalf or sent as a group mailbox by choosing an appropriate signature with the Use this signature button in the Web Add-in’s pane. This scenario requires you to create a separate signature rule, which lists group delegates as senders.

To start, sign in at app.codetwo.com and create a new client-side rule (Fig. 10.).

Fig. 10. Creating a new client-side signature for the shared mailbox users.

Go to the Senders step. Click Add > Group members (inside organization) and select a group containing users with the delegate rights to the group mailbox for which you want to create a signature (e.g. Sales and Marketing, as shown in Fig. 11.). Confirm by clicking OK.

Fig. 11. Selecting a group consisting of users with delegation permissions to this group’s mailbox.

Go to the Logic step, unselect the Set this signature as default for new messages and Set this signature as default for replies and forwards options, as shown in Fig. 12.

Fig. 12. Setting up the signature rule so that the signature template for the group mailbox is not added by default to all emails.

Finally, go to the Design step and create a signature template for the group mailbox, as described here.

Apply your changes by clicking Save & Publish.

Result

In server-side mode, if a user sends an email as a shared mailbox (default), CodeTwo Email Signatures for Office 365 recognizes the email as sent by the shared mailbox and adds a signature defined for this mailbox. If a user sends an email on behalf of a shared mailbox, the program adds the signature defined for this user. Both situations are shown in Fig. 13. 

Fig. 13. Emails sent on behalf of (left) and as (right) a shared mailbox with server-side signatures added by CodeTwo.

In client-side mode, once a user selects a shared / group mailbox in the From field, they need to open the CodeTwo Outlook add-in’s pane and click the Use this signature button next to a signature they want to use (Fig. 14.), i.e. the one configured for the selected mailbox. Learn more about using the add-in

Fig. 14. The available client-side signatures are displayed in the CodeTwo Signatures pane in Outlook and OWA.

See also

How to add personalized email signatures to emails sent from shared mailboxes