Hi Maren Ezhno,
go through this CRM_LOY_MSH_EMAIL_ADDRESS. function module pass the ID in to the IV_MEMB_ID you will get the email and address of the particular ID.
another function module CRM_EMAIL_READ_PARTNER_ADDRESS pass the partner or order number then you will get the ES_PARTNER_ADDRESS in that there is a email field.. you can get that field using read table.
Thanks & Regards,
Srinivas.