How to exclude signatures when an email is sent to a specific user, group or domain

Problem:

You would like to configure CodeTwo Email Signatures 365 so that signatures are not added to emails sent to specific recipients (email addresses, users, groups, etc.).

Solution:

It is possible to stop adding email signatures to messages sent to specific recipients. How you do it depends on whether you use CodeTwo Email Signatures 365 in cloud (server-side), Outlook (client-side), or combo mode (learn more about signature modes). Use the links below for guidelines:

• Cloud mode
• Outlook mode
• Combo mode

Cloud (server-side) mode

Suppressing email signatures for specific recipients can be achieved in many ways. You can:

• Use the Recipients exceptions in the signature management app. This gives you a lot of personalization options, e.g. excluding email addresses, domains or internal groups. For details, visit the user's manual.
• Use keywords to suppress email signatures. This approach may be better if you need to remove signatures at will, with no specific exception patterns. See this article in user's manual for guidelines.
• Exclude emails sent to specific users from being routed through CodeTwo by modifying the CodeTwo transport rule in Exchange Online. Read on to learn how to do it.

The CodeTwo software is designed in such a way that an email needs to be routed through the CodeTwo service to get a cloud signature. If you want to exclude email signatures from emails sent to specific recipients, you can exclude these emails from being routed through our service.

Users whose emails are routed through the CodeTwo service (scope of senders) are specified when you configure Exchange Online connectors (learn more). The specified scope of senders is automatically added to the CodeTwo Exchange Online transport rule, which redirects your mail flow through the CodeTwo service.

To exclude emails sent to specific recipients from being routed through the CodeTwo service, you need to exclude these recipients from the CodeTwo transport rule in Exchange Online. To do so, an admin of your Microsoft 365 (Office 365) organization needs to follow the steps below.

1. Sign in to the Exchange admin center as a global administrator or Exchange administrator.
2. Go to Mail flow > Rules. Find the CodeTwo Exchange transport rule, click it and use the Edit rule conditions button to start editing the rule (Fig. 1.).

Fig. 1. Opening the CodeTwo Exchange transport rule for editing.

3. To exclude emails sent to specific recipients (such as email addresses, users, or groups) from the CodeTwo transport rule, you need to add the condition(s) covering these recipients under the Except if section of your rule (Fig. 2.) and save your changes. See examples below.

Fig. 2. Adding a new exception to the CodeTwo Exchange transport rule.

Examples

• How to prevent emails sent to a specific user (email address) from getting signatures
• How to prevent emails sent to members of a specific group from getting signatures
• How to prevent emails sent to a specific domain from getting signatures
• How to prevent emails sent to specific group mailboxes from getting signatures

How to prevent emails sent to a specific user (email address) from getting signatures

Add a new exception by clicking the + button (see Fig. 2.) and choose The recipient > is this person (Fig. 3.). In the pane that opens, select users from your organization or add other email addresses. To add an external email address, type it in the Select members text field. Finally, click Save twice to close the pane and submit your changes to the CodeTwo Exchange transport rule.

Fig. 3. Adding an exception based on individual message recipients to the CodeTwo transport rule.

How to prevent emails sent to members of a specific group from getting signatures

Add a new exception by clicking the + button (see Fig. 2.) and choose The recipient > is a member of this group (Fig. 4.). In the pane that opens, add any groups in your organization and click Save twice to close the pane and submit your changes to the CodeTwo Exchange transport rule. 

Once you complete the steps above, emails sent to the members of these groups will not be routed through the CodeTwo service (these emails will not get signatures).

Fig. 4. Adding members of specific groups to the exceptions of the CodeTwo transport rule.

How to prevent emails sent to a specific domain from getting signatures

There are several ways to define an exception based on the recipient's domain. For example, you can add a new exception (by clicking the + button, as shown in Fig. 2.) and choose one of the following options:

• The recipient > address includes any of these words - in the pane that opens, type a domain name (e.g. domain.com) in the text field, and click Add and Save (Fig. 5.).
• The recipient > address matches any of these text patterns, type a domain name using regular expressions (e.g. @domain\.com$), and click Add and Save. Learn how to use regular expressions
• The recipient > domain is, and type a domain name (e.g. domain.com), and click Add and Save.

Finally, click Save once again to submit your changes to the CodeTwo Exchange transport rule.

Fig. 5. Adding specific domains to the exceptions of the CodeTwo transport rule.

How to prevent emails sent to specific group mailboxes from getting signatures

Add a new exception by clicking the + button (see Fig. 2.) and choose The message > To or Cc box contains this person (Fig. 6.). In the pane that opens, select any groups in your organization and click Save twice to close the pane and submit your changes to the CodeTwo Exchange transport rule.

Fig. 6. Adding a specific group's mailboxes to the exceptions from the CodeTwo transport rule.

Outlook (client-side) mode

In Outlook mode, CodeTwo signatures are synchronized to Outlook (desktop & mobile) and Outlook on the web (OWA) through the dedicated add-in. CodeTwo Outlook signatures are either automatically added to an email or a user can add them manually. If a default signature is set for a given user, it will be automatically added in the compose message window once the user clicks New message, Reply, Reply All or Forward button. In such a case, the user needs to manually delete the signature if they do not want it in their email.

Combo mode

Adding signatures in combo-mode depends on the signature rule settings (managed at app.codetwo.com) that apply to a specific user and the email client they use. If a user uses Outlook (desktop or mobile) or Outlook on the web (OWA), Outlook (client-side) signature rules apply. If a user uses another mail client, cloud (server-side) signature rules apply.

See also:

Conditions and exceptions available in Exchange Server

How to add or remove email signatures using keywords in CodeTwo Email Signatures 365