public async Task AddUnsubscribeRecord(string email) { try { long recordcount = await _Unsubscribe.CountDocumentsAsync(x => x.Email == email); if (recordcount == 0) { Unsubscribed newRecord = new Unsubscribed() { Id = ObjectId.GenerateNewId().ToString(), Email = email?.ToLower(), UnsubscribedAt = DateTime.UtcNow }; await _Unsubscribe.InsertOneAsync(newRecord); } } catch (Exception ex) { throw ex; } }