它无法发送邮件到hMailServer错误554 Your message was received but it could not be saved. Please retry later 554 Your message was received but it could not be saved. Please retry later 。
554 Your message was received but it could not be saved. Please retry later
检查安装hMailServer的设备（如Windows Server）的磁盘空间。 如果它是0字节空闲的，则邮件不能被传送。