Fortinet 3.0 MR4 User Manual

Use this command to enable or disable the use of MX record for this domain. This command is 
available in gateway and transparent modes only.

set policy <fqdn_str> modify mxflag {0 | 1}

Setting mxflag to 0 enables the MX record for this domain.

<fqdn_str> 

is the fully qualified domain name.

New.