Thanks for replying! My issue is now actually resolved - USPS confirmed that my taxes did indeed arrive. The delay in tracking info was because it's a PO box and the IRS collect letters in batches. The address is "Department of Treasure, Internal Revenue Service, Austin, TX [social security number removed]" and I didn't owe any payment, for reference. Thanks so much for getting back to me though - I do appreciate the offer to help!
