Defining X-SMTPAPI header - sendgrid

Question

Question 1: Do I need to strictly follow the order while defining the X-SMTPAPI
header related order mentioned in the doc ?
The doc(http://sendgrid.com/docs/API_Reference/SMTP_API/) mentions it like this:
{
"to": [
"ben#sendgrid.com",
"joe#sendgrid.com"
],
"sub": {
"%name%": [
"Ben",
"Joe"
],
"%role%": [
"%sellerSection%",
"%buyerSection%"
]
},
"section": {
"%sellerSection%": "Seller information for: %name%",
"%buyerSection%": "Buyer information for: %name%"
},
"category": "Orders",
"unique_args": {
"orderNumber": "12345",
"eventID": "6789"
},
"filters": {
"footer": {
"settings": {
"enable": 1,
"text/plain": "Thank you for your business"
}
}
}
}
So, my email header in this case would look like the following in coldfusion:
<cfset myheaderdefinition = XMLFormat('X-SMTPAPI|{
"to": [
"ben#sendgrid.com",
"joe#sendgrid.com"
],
"sub": {
"%name%": [
"Ben",
"Joe"
],
"%role%": [
"%sellerSection%",
"%buyerSection%"
]
},
"section": {
"%sellerSection%": "Seller information for: %name%",
"%buyerSection%": "Buyer information for: %name%"
},
"category": "Orders",
"unique_args": {
"orderNumber": "12345",
"eventID": "6789"
},
"filters": {
"footer": {
"settings": {
"enable": 1,
"text/plain": "Thank you for your business"
}
}
}
}
') >
Question #2: Does the way I have defined my header looks good?
More clarifications on Question #1:
1.1 Do I need to use to,sub,role,section etc in the same order as mentioned? OR can I skip one of these if I am not using these?
1.2 How would I determine what sendgrid is expecting for unique_args and other fields?

Answer 1

1 - 1.1 You may use any number of SMTPAPI parameters in any order you wish, in the JSON object you provide SendGrid. You may omit those you are not using. The sample provided in the SendGrid docs is only that, not a requirement.
1.2 unique_args and the rest of the parameters are fields only meant for you. SendGrid is not expecting anything. As you provide parameters SendGrid will execute on them as explained in SMTPAPI Documentation.
2 Your setup does not look right, although I am not intimately familiar with ColdFusion, it does not look as though you are correctly defining an email header. I would point toward my previous answer to your previous question as to how to set that up.
However, based on this and previous questions, I must ask, are you sure you want to use SendGrid's SMTPAPI or just use SMTP to send email to SendGrid?
The SMTPAPI provides much additional functionality to email, based upon parameters provided to it through a JSON object. However, sending through SMTP simply transports your message to SendGrid using the protocol of SMTP.
EDIT: To further check your SMTPAPI Header, you may want to use the SMTPAPI Header Validator