The Putnam County Sheriff's Office is reminding residents to avoid using their own mailboxes for mail pickup.

Officials say it's because of recent cases of mail theft in the Putnam Valley area.

Residents say they've had checks stolen from their mailboxes. They say the thief then changed the checks to a much higher amount before cashing them.

Law enforcement says to only use secure U.S. Postal Service mailboxes when mailing checks.