I must say, due to mwestwood's exquisite answer, there is not too much to add; however, I can give a couple different tidbits. Of course, the term "recalled to life" is the carrier's, Jerry Cruncher's, message during his return on horseback from the Dover stage. Jerry's message reaches Jarvis Lorry right before he heads to France and is kind of a secret message.
The message is truly a mystery to Lorry. Even Jerry thinks it is a "strange message." It is only the reader that truly understands it and how it connects to "Mam-selle" at Dover. It is about Manette's rescue from his imprisonment at the Bastille. When he was let go, Manette was in poor condition, and his release gives him a new lease on life (especially to live in peace with his daughter, Lucie).
In conclusion, it is important to note that this message of "recalled to life" introduces one of the main themes of the novel: the dual nature of the body and the spirit. Note how Manette is bodily "recalled to life" from the Bastille after many years. Further, Sydney Carton is spiritually "recalled to life." He goes from a being a person of ill-repute (a simple barrister) to an upstanding citizen when he falls in love with Lucie Manette. This is proven when Sydney sacrifices his own life.