bash和telnet测试电子邮件

Question

我想知道电子​​邮件地址是否有效.

我通过telnet telnet完成了这个,见下文

$ telnet mail.example.com 25
Trying 0.0.0.0...
Connected to mail.example.com.
Escape character is '^]'.
220 mail.example.com Mon, 14 Jan 2013 19:01:44 +0000
helo email.com
250 mail.example.com Hello email.com [0.0.0.0]
mail from:blake@email.com
250 OK
rcpt to:gfdgsdfhgsfd@example.com
550 Unknown user

有了这550个请求,我知道该地址在邮件服务器上无效......如果它有效,我会得到如下的响应:

250 2.1.5 OK 

我如何在shell脚本中自动执行此操作？到目前为止,我有以下内容

#!/bin/bash
host=`dig mx +short $1 | cut -d ' ' -f2 | head -1`
telnet $host 25 

谢谢!

Answer 1

试着这样做:

[[ $@ ]] || {
    printf "Usage\n\t./$0 domain <email> <from_email> <rcpt_email>\n"
    exit 1
}
{
    sleep 1
    echo "helo $2"
    sleep 0.5
    echo "mail from:$3"
    sleep 0.5
    echo "rcpt to:$4"
    echo
} | telnet $1 25 |
    grep -q "Unknown user" &&
    echo "Invalid email" ||
    echo "Valid email"

用法:

./script.sh domain email from_email rcpt_email