“Mail delivery failed: returning message to sender” Hatası

Selamlar, Bazen mail gönderdiğimizde aşağıdaki tarzda bir hata mesajı alırız. This message was created automatically by mail delivery software. A message that you sent could not be delivered to one or more of its recipients. This is a permanent error. The following address(es) failed: xxxx@xxxx.xxx SMTP error from remote mail server after end of data: host mail.xxxxxxxxx.com [64.128.xxx.xxx]: 554 Service unavailable; Client host [linux.xxxx.net] blocked using Barracuda Reputation; http://www.barracudanetworks.com/reputation/?r=1&ip=95.14.xx.xx ——…