Operating system name and version: Debian
Version of smsd: 3
Smsd installed from: package repository
Name and model of a modem / phone: Huawei
Interface: USB

After several years of working recently I receive numerous entries of the same sms in the incoming spool folder. Up to 4 entries can appear, sometimes within 40 minutes' interval.
Could somebody guide me how to tackle this problem?
Thank you in advance!