offlineimap: 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 CentOS possible default full paths are:

/usr/bin/offlineimap - from package: offlineimap

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/offlineimap - from package: offlineimap

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

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