Get PartyList lookup field in Email/Activities entity update partyid record
Get the partylist lookup value and check the lookup value is contact and update the contact Entity fromActivityParty = targetEntity.GetAttributeValue<EntityCollection>("from").Entities .Where(x => x.GetAttributeValue<EntityReference>("partyid")?.LogicalName == "contact") .FirstOrDefault(); if (fromActivityParty == null) return; EntityReference contactReference = fromActivityParty.GetAttributeValue<EntityReference>("partyid"); Entity contact = new Entity("contact", contactReference.Id); contact["fullname"]= "ApyCRM"; service.Update(contact);