As a general rule, it's difficult to sue the US Postal Service for lost, delayed, or mishandled mail. But a case before the US Supreme Court involving a Texas landlord who claims her mail was deliberately withheld for two years is looking to challenge that, the AP reports, in a proceeding the cash-strapped Postal Service says could prompt a deluge of lawsuits over the very common, if frustrating, phenomenon of missing mail. That concern takes on particular resonance during the holiday season, when the volume of mail—billions of sentimental items including Christmas cards and Black Friday purchases—ramps up.