FAQ / General Debugging / Q0019
Q0019
Question
There seems to be a problem in the string expansion code: it doesn't recognize references to headers such as ${h_to}.
Answer
The only valid syntax for header references is (for example) $h_to: because header names are permitted by RFC 2822 to contain a very wide range of characters. A colon (or white space) is required as the terminator.
FAQ / General Debugging / Q0019