In any case you need to define queues, see
Configuring Providers for details.
I assume that in playSMS you cannot define different headers (in message file) for different users, so external solution is required. This script may do the job, define it as a checkhandler in the global part of smsd.conf:
checkhandler = /usr/local/bin/smsd_checkhandler_playsms.sh#!/bin/bash
# This sample assumes that the filename is in the following format,
# and for example 1 or 12 defines a playSMS user:
# out.PV.1.222
# out.PV.12.333
tmp=${1##*/}
if [ "${tmp:0:7}" == "out.PV." ]; then
tmp=${tmp:7}
id=${tmp%%.*}
queue=""
case "$id" in
1) queue="QUEUE1";;
7) queue="QUEUE2";;
8|9|10) queue="QUEUE3";;
esac
if [ -n "$queue" ]; then
tmp=`mktemp /tmp/smsd_XXXXXX`
cp "$1" $tmp
formail -f -I "Queue: $queue" < $tmp > "$1"
unlink $tmp
fi
fi
exit 0
'bash' Syntax Highlight powered by GeSHi Adjust correct queue for correct used id's inside the case -esac.