Yes, the seams can be resealed, but it is not cost effective and Gutter Masters cannot warranty resealed seams. With an older seamed gutter system that leaks, in most cases it should be replaced with a new gutter system and a full warranty.
Yes. Gutters Masters will replace the corner, check for proper water flow and adjust your gutter as needed. Several other aspects of the gutter system need to be checked to take care of this problem. Call Gutter Masters and set up an appointment to have that leak fixed.