Approval status not available on Insert field (CRMSDK) on email templates.

It is by designed that the field Approval Status is not available as an option under the insert field of an email template. As an alternate solution, you can create a custom field and use the custom field to populate the value of the Approval Status.

1. Navigate to Customization > Lists, Records & Fields > Transaction Body Fields > New
Label: Bill Approval
Type: Free-Form Text
Store Value: T
Applies To: Purchase
Display > Subtab: Main

2. For existing records, perform a mass update to set the value on the field.
a. Lists > Mass Update > Mass Updates > General Updates > Bill.
b. Mass Update Fields tab > Check Apply for the Bill Approval Field.
c. For the Formula column, use {approvalstatus}
d. Click Preview then Perform Update

3. To set the value for new records on the custom field, create a Workflow or Script
a. Customization > Scripting > Workflows > New.
b. Name: Set Field Value Bill Approval
c. Record Type: Transaction
d. Sub Type: Vendor Bill
e. Release Status: Testing/Released
f. Event Based: Create, Update
g. Create new State.
h. Then create new Action: Set Field Value
i. Trigger On: Entry
j. Field: Bill Approval
k. From Field > Record : Current Record
l. From Field > Field: Approval Status