Comment: Post card must contain Something to do with Imbolic / Lughnasadh depending what side of the world your partner is from.
i am from southern hem
Response: If I remember correctly, I sent card with picture of serpent. Serpent is symbol of Brigid, goddess worshipped at Imbolc. for example, it is listed here http://www.goddessandgreenman.co.uk/imbolc-candlemas (and wikipedia too plus several other sites about wiccan / pagan traditions). I am sorry if this is not Imbolc enough for you. I can send you new card, if that is what you wish.