Configuration Summary:
1) Enable centralized quarantine on the ESA appliance(s):GUI > Security Services > Spam Quarantine >Check Enable External Spam Quarantine
2) Disable the local quarantine(s):GUI > Monitor > Spam Quarantine> Uncheck Enable Spam Quarantine
3) Submit and Commit Changes.
https://www.cisco.com/c/en/us/support/docs/security/email-security-appliance/118555-qa-esa-00.html

After creating a signing profile, you must enable DKIM in the mail flow policy for outbound emails.
This ensures that the Cisco Secure Email Gateway signs outgoing messages with DKIM for the specified domains.

You can create some text resources with both HTML-based and plain text messages, such as Disclaimers.
When you add or edit an HTML-based text resource, the GUI includes a rich text edit that allows you to enter rich text without having to manually write HTML code.
You can switch between the rich text editor and HTML code by clicking the Code View button.
https://www.cisco.com/c/en/us/td/docs/security/esa/esa11-1/user_guide/b_ESA_Admin_Guide_11_1/b_ESA_Admin_Guide_chapter_010110.html?bookSea rch=true

Determining Which Interface is Used for Mail Delivery
Unless you specify the output interface via the deliveryconfig</code> command or via a message filter ( alt-src-host ), or through the use of a virtual gateway, the output interface is selected by the AsyncOS routing table.
https://www.cisco.com/c/en/us/td/docs/security/esa/esa11-1/user_guide/b_ESA_Admin_Guide_11_1/b_ESA_Admin_Guide_chapter_011001.html?bookSea rch=true

When you configure your appliance to work with an LDAP directory, you must complete the following steps to configure your AsyncOS appliance for acceptance, routing, aliasing, and masquerading.