flap 300 and the primary flag 185 signaling presence of mail for pick up operate independently of one another and each could be present in a mailbox without the other and still considered within the scope of the invention herein moreover in certain embodiments the secondary flag is not a required part of the delivered mail detection mechanism in that flap 300 can function to enable the locking mechanism without providing an external u201c delivered mail present u201d signal further description of the operation and functioning of the device follows the present invention provides for the obstructing or a blocking member be interposed between the spring loaded latching means on the door and the catch on the enclosure portion which prevents the spring loaded latching means from engaging the catch so that the access door can be closed but will remain unlocked until the interposed obstructing member is removed from between the spring loaded latching means and the catch these movable obstructing members i e tab 310 attached to flap 300 and obstructing member 525 attached to primary flag 185 are preferably in the form of a metal blade portion the blade configuration facilitates that either blade portion or both may be in an obstructing position and either one may be moved in and out of the obstructing position with the other one in the obstructing position when the outgoing mail signaling device the primary flag 185 is raised to.