1,367. Being Notified of a Death
218:1 A person observes mourning even when informed of a relative's passing by: a lone witness; a witness who heard from another witness; a non-Jew speaking without realizing the impact of his statement.
218:2 If a person receives a letter informing him of the death of a relative and it does not specify whether the person died within thirty days, if the letter-writer is not learned, one must assume that the relative died shortly before the letter was written, and he must mourn accordingly. However, if the writer is learned in Torah, he may assume that it was written after thirty days passed, because if he thought the letter would arrive within thirty days, he would have been more specific. If the deceased was the letter-recipient's parent, then the accepted practice is to inform him immediately and he must mourn.