Definitions for "Mutual reception"
Two planets placed in each other's sign of essential dignity are in mutual reception, " en rapport". Mutual reception provides a harmonious link between planets not in aspect and strengthens the aspect if one exists.
When each of two planets is in the sign ruled by the other, a relationship is formed between the two that acts like a conjunction. For example, if Mercury (ruler of Gemini) is in Sagittarius, and Jupiter (ruler of Sagittarius) is in Gemini, the two planets are drawn together by virtue of their shared meanings, leading to beneficial effect.
When each of two Planets is in the Sign ruled by the other, a relationship is formed that acts much like a conjunction. (example; The sun [ruled by Leo] is in Cancer and the Moon [ruled by Cancer] is in Leo.)