White Salmon residents could soon get free access to post office boxes, following years of efforts to address inequities in local mail service.  The U.S. Postal Service is moving forward with changes that could qualify many residents for what’s known as Group E P-O Box service, allowing them to receive mail at no cost.  The City says residents are beginning to receive official notifications from the Postal Service outlining their options and eligibility.  City officials are encouraging residents to watch for those letters and follow the instructions provided.  Mayor Marla Keethler calls the development a long-awaited step forward, noting that many White Salmon residents have had to pay for post office boxes for decades because home mail delivery wasn’t available.  The progress follows years of advocacy by residents and city leaders, along with support from local postal officials, state Senator Paul Harris, and Washington’s U.S. Senators Patty Murray and Maria Cantwell.  The Postal Service will determine individual eligibility and provide details about how the changes will be implemented.