The story of a quirky quartet of civil servants in the Dead Letter Office who transform themselves into an elite team of lost-mail detectives. Their determination to deliver the seemingly undeliverable takes them out of the post office into an unpredictable world where letters and packages from the past save lives, solve crimes, reunite old loves and change futures by arriving late but always miraculously on time. The intrepid team is led by the charming and idiosyncratic Oliver, who still considers the stamped and mailed letter to be the gold standard of human communication. His two hapless sidekicks are thrown for a loop when a beautiful, no-nonsense technophile named Shane is mistakenly transferred to their inner sanctum and inspires the lovable crew to step up in a risky and unorthodox way.
When she joined the New York Postal Service, Shane was mistakenly assigned to identify pending mail which she had to complete with poorly worded addresses for their delivery. The case of a letter, written a year earlier, particularly touches her. It is about a love letter from Kelly to Charlie whom she has just met and with whom the love at first sight was total. Knowing that she is ill, Kelly gives her an appointment, if she is still alive, a year after their meeting.
An emotional holiday story in which the Postables work overtime to help a struggling family find hope on Christmas Eve.
The Postables, including Oliver, Shane, Rita and Norman, explore the mystery of true love as they deliver divorce papers to one couple the same day Oliver's missing wife reappears.
The Postables work against the clock decoding a letter to rescue a soldier in Afghanistan and reunite her with her family, while Rita competes for the National Miss Special Delivery title in Washington, D.C.
Oliver's (Eric Mabius) Divine Delivery Theory is put to the test when he and the POstables (Kristin Booth, Geoff Gustafson and Crystal Lowe) seem to be unable to deliver a damaged letter from a military veteran that's a matter of life and death. They've always been able to deliver mail by the grace of God right at the time it's needed most. While Oliver's faith is not shaken, his father Joe (Gregory Harrison) questions this divine theory. As Norman and Rita go on a road trip to pursue leads in the urgent veteran's letter, their trip takes them to the next level of their relationship and leads them to the place they're needed the most. Meanwhile Oliver and Joe go backpacking on a father son bonding trip during which a serious injury puts both their lives at risk. After Oliver doesn't show up at work, Shane spearheads a rescue mission and calls Oliver's police officer friend Dale to help. When all seems lost, what's most important is found. To everything there is a season, a time for every purpose under heaven.
The Postables take a road trip in an old Winnebago in order to track down a small boy who they fear may have been kidnapped. The discovery of a 1980's era instant camera and the unusual photographs it contains, send our team on a wild ride across Colorado using the pictures as a guide.
When plans for Rita and Norman’s long-awaited wedding begins falling apart days before their nuptials, their challenges inspire changes that make their wedding more meaningful. Meanwhile, Shane convinces Oliver that the team should urgently focus on finding clues to deliver a package containing a wedding dress.