Reference:
https://www.cisco.com/c/en/us/td/docs/security/esa/esa12-0/user_guide/b_ESA_Admin_Guide_12_0/b_ESA_Admin_Guide_12_0_chapter_011001.html one of the steps to accept mail for additional internal domains on the Cisco ESA is to choose Network > SMTP Routes and enter the new domain and the corresponding destination host IP address1. This can also be done using the smtproutes command in the CLI1. The other commands (deliveryconfig, dsestconf, and altrchost) are not related to this task.