you should give some defualt sendgrid_header when user didn't set for a newly installed system

[hlxwell]

Set this for all mailer is troublesome:

sendgrid_header do
category "itjob_production"
filters {
opentrack "enable" => 1
clicktrack "enable" => 1
subscriptiontrack "enable" => 0
template "enable" => 0
footer "enable" => 0
}
end