BANNER HOST

TCP/IP-channel-specific options: BANNER_HOST (string)
This option applies to both the SMTP/LMTP server and the SMTP/LMTP client. If specified, this value takes precedence over even a    for  the name used in the 220 banner (SMTP/LMTP server) and on the  HELO/EHLO/LHLO line (SMTP/LMTP client).

See also:
 * local_host_alias Option
 * BANNER_REVERSE_HOST
 * TCPIP-channel-specific options