Commentinc, commentmap, commentomit, commentstrip, commenttotal, sourcecommentinc, sourcecommentmap, sourcecommentomit, sourcecommentstrip, sourcecommenttotal Channel Options

Comments in address message headers
The MTA only interprets the contents of header lines when necessary. However, all registered headers containing addresses must be parsed in order to rewrite and eliminate shortform addresses and otherwise convert them to legal addresses. During this process comments (strings enclosed in parentheses) are extracted and may optionally be modified or excluded when the header line is rebuilt.

On destination channels, this behavior is controlled by the use of the,  ,  ,  , and   channel options. tells the MTA to retain comments in header lines. It is the default. tells the MTA to apply the   mapping table to comments in addressing header lines if such a mapping table exists, while if no such mapping table exists then   is equivalent to. tells the MTA to remove any comments from addressing headers, e.g., To:, From:, Cc: headers, etc. tells the MTA to remove any comments from all headers, except Received: headers; as such, this option is not normally useful or recommended. And finally,  tells the MTA to strip any nonatomic characters from all comment fields.

On source channels, this behavior is controlled by the use of the,  ,  ,  , and   channel options. tells the MTA to retain comments in header lines. It is the default. tells the MTA to apply the   mapping table to comments in incoming addressing header lines if such a mapping table exists, while if no such mapping table exists then   is equivalent to. tells the MTA to remove any comments from addressing headers, e.g., To:, From:, Cc: headers, etc. tells the MTA to remove any comments from all headers, except Received: headers; as such, this option is not normally useful or recommended. And finally,  tells the MTA to strip any nonatomic characters from all comment fields.

These options can be applied to any channel.

See also:
 * use_comment_strings MTA Option
 * COMMENT_STRINGS mapping table
 * Headers channel options
 * Channel options