citmail: command not found

Have You tried accessing the binary with the full path?

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

[root@server ~]# echo $PATH

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/lib/debug/usr/sbin/citmail - from package: citadel-dbg
/usr/sbin/citmail - from package: citadel-server

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