[Player name],
As a mark of the high esteem in which you are held by Jarl [Hold name], [he/she] has instructed me to offer you an opportunity to become a landowner in [Hold name]. A choice piece of undeveloped land in the hold has just become available. Please contact me if you are interested in purchasing it.
Your humble servant, etc., etc.,
[Steward name], Steward to Jarl [Jarl name] of [Capital city]