Disclaimer: Tolkien's the genius, not me.
Messengers were leaving ahead of them from Rohan, bearing letters and messages to Rivendell and Lothlórien, that preparations for the travelers’ arrival could be made. Frodo quickly scribbled a note to Bilbo, assuring him that all was well, and that he had much to tell him when they met again, about Merry and Pippin’s new positions in Gondor and Rohan – and especially about Gollum’s unexpected role in the Quest.
After signing his name, Frodo had another thought.
PS: You might want to see about adding pages to the Red Book. There is so much more it will need to hold!