port outdated out of date ?

Doing a port -v sync, I knew thare had been some update on the mutt-devel port. However port outdated did not show any change, mutt still being in version 1.5.14 Looking at the portfile it was version 1.5.15, so I upgraded it. It seems the PortIndex file was not up to date, is there a way to update it client side ? -- Erwan