Indexing arbitrary mail headers

By default the Recoll mail handler only processes a subset of email headers (From, To, Cc, Date, Subject). It is possible to index additional headers by specifying them inside the fields configuration file, inside the configuration directory (typically ~/.recoll/).

Lengthy explanations are not really needed here, and I’ll just show an example (duplicated from the configuration section of the manual):

# Index mailmytag contents (with the given prefix)
mailmytag = XMTAG

# Store mailmytag inside the document data record (so that it can be
# displayed - as %(mailmytag) - in result lists).
mailmytag =

# Extract the X-My-Tag mail header, and use it internally with the
# mailmytag field name
x-my-tag = mailmytag


  • The mail filter will only process the first instance for a header occurring several times.

  • No decoding will take place (ie for non-ascii headers which would have some kind of encoding).