Returns the value of the Content-ID header from the stream supplied as argument, if such header exists; otherwise, it returns the value of the default argument.
get-mime-content-id(s:stream, default:string="") -> string  | 
Name  | 
Type  | 
Description  | 
|---|---|---|
s  | 
stream  | 
Specifies the input stream.  | 
default  | 
string  | 
Specifies the value to return when Content-ID header does not exist. By default, this is an empty string.  | 
Let's suppose that stream msg has the header Content-ID: <root.attachment>. The expression
get-mime-content-id(msg, "")  | 
returns "<root.attachment>" in this case. If no such header exists, the expression above returns an empty string (the value of the second argument).