I got this error even though I had an smsbox defined. Unfortunately I had forgotten to create the smsbox-route group, so this is a very quick fix: #--------------------------------------------- ## SMS ROUTING ##--------------------------------------------- group = smsbox-route smsbox-id = mainbox smsc-id = ztemodem-smsc-group sim-buffering = false ... continues ... Just make sure the id's matchup, so my smsbox group begins with this: #--------------------------------------------- ## SMS BOX ##--------------------------------------------- group = smsbox smsbox-id = mainbox ... continues ... And my SMSC looks like this: #--------------------------------------------- ## GSM MODEM SMSC ##--------------------------------------------- group = smsc smsc-id = ztemodem-smsc-group ... continues ... This successfully cleared the "smsbox_list empty" error and allowed messages to be delivered properly. Kannel had until then been able to send messages and receive delivery...