[Dovecot] sieve rule help

Dear All, I am using dovecot-2.0.0 version and all my sieve filters are working perfectly except the following one.

I am trying to flag message coming from jagdish@example.net mail id.

require ["fileinto","envelope","reject","vacation","imap4flags","relational","comparator-i;ascii-numeric","regex","body","date"];

if address :contains "From" "jagdish@example.net" { keep :flags ["Flagged"] ; }

Is it possible to make it work without using addflag to add a flag ?