我正在尝试使用mailx命令，但由于防火墙，它无法工作。我尝试mailx在终端上使用，但它发出警告，如下所示：
send-mail: warning: inet_protocols: IPv6 support is disabled: Address family not supported by protocol
send-mail: warning: inet_protocols: configuring for IPv4 support only
postdrop: warning: inet_protocols: IPv6 support is disabled: Address family not supported by protocol
postdrop: warning: inet_protocols: configuring for IPv4 support only