Max header blocks MTA option

Message size MTA options:  (integer)
The  MTA option causes truncation of the original, incoming message header after the specified number of blocks (by forcing additional, supposedly header material, into the message body). The default is no limit, but see also the  and   MTA options. The,  , and    MTA options provide some protection against denial-of-service attacks in the form of messages with extravagantly large/long headers.

See also the  channel option, limiting how much of the header the MTA will process.

See also:
 * Message size MTA options
 * max_header_lines MTA Option
 * header_limit MTA Option
 * maxprocchars Option