How does notmuch detect the presence of attachments?

[moabi2000]

Hi,

Two questions:

1) How does  notmuch detect the presence of attachments? I have some
messages that have attachments (which I can see and open when reading
the message), but for which the 'attachment' flag is not set (and
therefore don't show up in a search like "from:myfriend AND
attachment:pdf"). How can I try to work out what is going on?

2) Is there an option for notmuch to also index the text of
attachments (like recoll does, which also uses xapian)? People tend to
save attachments with really useless filenames (report2.pdf...), what
I'd like to be able to do is a search like "from:mycolleague AND
attachment:pdf AND attachmentcontains:ourproject"

Thanks for your help. Notmuch is already very useful!

M.