This task requires permissions that are found in all default security roles Defined sets of privileges.The security role assigned to a user determines which tasks the user can perform and which parts of the user interface the user can view. All users must be assigned at least one security role in order to access the system.. More information about specific permissions and performing this task while offline: E-mail Permissions
If you want other users in Microsoft Dynamics CRM to respond to e-mail messages for you, you can allow them to do so on your behalf with you as the sender. To do this, select E-mail Router as your outgoing e-mail access type, and set the Send E-mail as Another User A privilege required to send e-mail on behalf of another user. This privilege is on the Business Management tab in Security Roles. option.
Important
If you select this option, other users will be able to send e-mail messages that display you as the sender with or without your knowledge.
To specify whether other users can send e-mails on your behalf:
Click the File tab, and then click Options.
In the Set Personal Options dialog box, click the E-mail tab.
In the Select whether other users can send e-mail for you section, select the Allow other Microsoft Dynamics CRM users to send e-mail on your behalf check box.