domainseqs: 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
/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/domainseqs - from package: embassy-domainatrix

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