incm: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/incm - from package: mew-beta-bin
/usr/bin/incm - from package: mew-bin

You may install the required package with command apt-get install {package}

Error in other languages:
incm: bevel nie gevind nie
incm: comandă negăsită
incm: comando não encontrado
incm: commande introuvable
incm: command not found
incm: käsku ei ole
incm: không tìm thấy lệnh
incm: komanda nerasta
incm: Kommando nicht gefunden.
incm: kommandot finns inte
incm: komut yok
incm: nie znaleziono polecenia
incm: níor aimsíodh an t-ordú
incm: no se encontró la orden
incm: no s'ha trobat l'ordre
incm: opdracht niet gevonden
incm: parancs nem található
incm: perintah tidak ditemukan
incm: príkaz nenájdený
incm: příkaz nenalezen
incm: команда не найдена
incm: командата не е открита
incm: 命令找不到
incm: コマンドが見つかりません