icedove: 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/icedove - from package: icedove

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

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