How to add signatures to emails sent from shared mailboxes

Learn how to configure CodeTwo Email Signatures 365 to add signatures to emails sent from shared mailboxes. You can set up:

• Cloud (server-side) signatures (added after email is sent) for messages sent as or on behalf of a shared mailbox.
• Outlook (client-side) signatures that are automatically added as you type an email, as shown in Fig. 1.

Fig. 1. Sending an email from a shared mailbox – CodeTwo Outlook signature updates automatically.

Personal signature or a dedicated shared mailbox signature?

With CodeTwo, you can set up two kinds of email signatures for shared mailboxes. Choose one of the options below based on what you need:

• Personal signatures – signatures with the sender’s details (name, job title, phone number, etc.) pulled from Entra ID (Azure AD), added to emails sent as / on behalf of shared mailboxes. See setup instructions
• Dedicated shared mailbox signatures – signatures that include information from the shared mailbox’s own Entra ID profile. See setup instructions

How to add a personal signature to emails sent from shared mailboxes

There are a few ways to set up personal signatures for users who send emails from shared mailboxes. Choose the option that best fits your needs and the signature mode you're using:

Outlook (client-side) and combo mode:

• Use one of your existing personal signatures
• Create a shared mailbox signature with the sender's personal details

Cloud (server-side) mode:

• Combine a native Outlook signature with a cloud signature added by CodeTwo

Use one of your existing personal signatures when sending emails from a shared mailbox

Before you begin, ensure the advanced setting Change CodeTwo Outlook (client-side) signatures to match the email address in the From field is disabled for the add-in in CodeTwo Admin Panel, as shown in Fig. 2. Learn more about this setting

Fig. 2. To keep your personal signatures in emails sent from shared mailboxes, disable this option.

Now, while composing an email in Outlook, if you select a shared mailbox address (instead of your personal one) in the From field, your personal signature will remain in the email (Fig. 3.).

Fig. 3. You get your personal signature when sending an email as or on behalf of a shared mailbox.

Create a shared mailbox signature with the sender's personal details 

Before you begin, ensure the advanced setting Change CodeTwo Outlook (client-side) signatures to match the email address in the From field is disabled for the add-in in CodeTwo Admin Panel, as shown in Fig. 2. Learn more about this setting

Now, create an email signature for the shared mailbox in CodeTwo Email Signatures 365. To do this, go to app.codetwo.com and create a new Outlook (client-side) signature rule. For detailed steps, check out this article.

In the Senders step, select who will send emails from the shared mailbox with this signature. You can either specify individual users or select a group whose members will get the signature, as shown in Fig. 4.

Fig. 4. Select the users for whom you want to set up a separate signature.

Go to the Logic step and unselect (clear) the Set this signature as default for new messages and Set this signature as default for replies and forwards options, as shown in Fig. 5. This ensures the signature you're setting up isn't automatically added to emails sent from a regular (user) mailbox.

Fig. 5. Leave these options unselected.

In the Design step, create a signature template that you want to use with shared mailboxes (see this quick guide for step-by-step instructions). Make sure your shared mailbox signature contains both:

• Sender's personal details (e.g. first and last name, job title, etc., as shown in Fig. 6.). This information is fetched from Entra ID (Azure AD) using placeholders.
• Fixed (non-changing) shared mailbox contact info.

Fig. 6. Example of a shared mailbox signature (with the user's personal data).

Click Apply & Close to save your signature design, and then Save & Publish to go live with your signature rule.

Now, when end users compose an email in Outlook, they can manually add the signature designed for the shared mailbox from the add-in pane, as shown in Fig. 7.

Fig. 7. Inserting the signature designed for a shared mailbox.

Combine a native Outlook signature with a cloud signature added by CodeTwo

You can use a combination of a native Outlook signature that contains only the sender's personal details and a cloud (server-side) email signature (added by CodeTwo) that includes the remaining information – company logo, marketing banner, contact details, etc. This cloud signature is added to all messages sent from, for example, shared mailboxes.

1. Set up a personal email signature in an email app

Users can create their own simple signatures in Outlook, e.g. by following the steps in this article: How to set up email signatures in Outlook 365.

Once set up, the personal signature can be added to emails automatically or manually by the user. For example, a signed reply from a shared mailbox in Outlook will look like the one in Fig. 8.

Fig. 8. A personal email signature added to a message sent from a shared mailbox.

2. Set up an email signature template for a shared mailbox in CodeTwo

Now, create an email signature for the shared mailbox in CodeTwo Email Signatures 365. To do this, go to app.codetwo.com and create a new cloud (server-side) signature rule. For detailed steps, check out this article.

In the Senders step (Fig. 9.), click Add > Selected senders under the top list and find your shared mailbox (e.g. [email protected]) in the picker that opens. Select it and confirm by clicking OK.

Fig. 9. Selecting a shared mailbox as a sender.

Configure the remaining rule conditions and options, and prepare a signature template that suits your needs.

When your signature rule and template are ready, click Save & Publish to go live with the new signature.

Now, after the email is sent from the shared mailbox, CodeTwo will add the signature set for this mailbox below the personal signature inserted in the email app (Fig. 10.).

Fig. 10. A personal signature added on top of a dedicated shared mailbox signature.

How to set up a dedicated shared mailbox signature

There are a few ways to set up an email signature for a shared mailbox. Choose the option that best fits your needs and the signature mode you're using:

Outlook (client-side) and combo mode:

• Create a dedicated Outlook signature for a shared mailbox

Create a dedicated Outlook signature for a shared mailbox

Before you begin, ensure the advanced setting Change CodeTwo Outlook (client-side) signatures to match the email address in the From field is enabled for the add-in in CodeTwo Admin Panel, as shown in Fig. 11. Learn more about this setting

Fig. 11. Enable this option to get a dedicated signature when you select a shared mailbox in the email's From address.

Now, let's create a new rule that will automatically add a different signature when you select a shared mailbox in the From field in Outlook. Go to app.codetwo.com and create a new Outlook (client-side) signature rule. For detailed steps, check out this article.

Next, go to the Senders step (Fig. 12.). Click Add > Selected senders under the top list and find your shared mailbox (e.g. [email protected]) in the picker that opens. Select it and confirm by clicking OK.

Fig. 12. A shared mailbox added to the senders condition of your Outlook (client-side) signature rule.

Go to the Logic step and select the options shown in Fig. 13. to make sure your signature is added automatically when changing the email address in the From field in Outlook.

Fig. 13. Ensure these options are selected so that the shared mailbox signature is added automatically.

Go to the Design step and create a signature template that will be added to emails sent from your shared mailbox. See this quick guide for step-by-step instructions

Finally, click Apply & Close in the editor to save your template, and then click Save & Publish in the rule creation wizard to go live with your new email signature.

Now, while composing an email in Outlook, if you select a shared mailbox address (instead of your personal one) in the From field, the signature will auto-update, as shown in (Fig. 14.).

Fig. 14. Sending an email from a shared mailbox – CodeTwo Outlook signature updates automatically.

Create a cloud signature for emails sent as a shared mailbox

First, 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 cloud (server-side) signature rule. For detailed steps, check out this article.

Next, go to the Senders step (Fig. 15.). Click Add > Selected senders under the top list and find your shared mailbox (e.g. [email protected]) in the picker that opens. Select it and confirm by clicking OK.

Fig. 15. Selecting a shared mailbox as a sender.

Configure the other rule conditions and options, and prepare a signature template that suits your needs.

When your signature rule and template are ready, click Save & Publish to go live with the new signature.

If a user sends an email as the shared mailbox specified in the new rule, CodeTwo will add a signature created for this mailbox (Fig. 16.).

Fig. 16. An email sent as a shared mailbox with cloud signature added by CodeTwo.

Create a signature for emails sent on behalf of a shared mailbox

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 cloud (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.