18. The system as claimed in claim 12 , further comprising: a header search component further comprising: a key receiving component for receiving a header name to be searched; a converting component for converting the header name to its canonical key using the mapping; and a sequential search component for searching for the canonical key in the message header list of a message using integer comparison.
12. A system, comprising: a converter for converting header names into a canonical form comprising a plurality of canonical keys, wherein each canonical key represents at least one equivalent header name, and wherein each canonical key has a string and an integer value; a map for mapping between the header names and the canonical keys; and a header search component for searching for a header name using the canonical key by sequential search using integer comparison.