# Guaranteed Delivery

For full end-to-end guaranteed delivery to SmartSockets from EMS, all the following conditions must be true:

- EMS senders must send persistent messages.
- The transport definition must set `delivery_mode` to `gmd_some` or `gmd_all` (as appropriate).

To preserve undelivered GMD messages in the EMS undelivered queue, see `preserve_gmd`. For import guarantees, see Guaranteed Delivery.

Copyright © Cloud Software Group, Inc. All rights reserved.