Output per-message (key,value) metadata. Each line starts
with "#= ", followed by a message id, and a space separated
list of key=value pairs. Ids, keys and values are hex encoded
if needed. See :any:`notmuch-properties(7)` for more details.
Output per-message (key,value) metadata. Each line starts
with "#= ", followed by a message id, and a space separated
list of key=value pairs. Ids, keys and values are hex encoded
if needed. See :any:`notmuch-properties(7)` for more details.