使用Shell脚本通过Telnet发送邮件
##介绍
有时候我们需要在linux服务器上对外发送邮件，但是该服务器又没有配置MTA（如postfix或sendmail)。 没有MTA，就不能使用mail命令来发送邮件，所有需要直接使用Telnet连接外部的MTA来发送邮件。
##脚本
#!/bin/bash
send_mail()
{
(sleep 2
echo "ehlo smtp.example.org"
sleep 2
sleep 1
echo "MAIL FROM:<noreply@example.org>"
sleep 2
arr=(${1//;/ })
for i in ${arr[@]}
do
set -x
echo "RCPT TO:<$i>"
set +x
sleep 3
done
sleep 1
echo "data"
sleep 2
echo "from:Your Name Here<noreply@example.org>"
#echo "to:<to@example.com>" I want to enable BCC here
echo "subject:${2}"
#enable HTML mail
echo "MIME-Version: 1.0;"
echo 'Content-Type: text/html; charset="UTF-8";'
echo ""
echo "${3}"
echo "."
sleep 2
echo "QUIT") | telnet "smtp.example.org" "25"
}
#please specify the value for to(seperated by ;) subject body
send_mail "mail1@example.com;mail2@example.org" "mail subject" "<html>
<body>
<h1>Hello</h1>
<p>this is a important <a href=\"www.baidu.com\">link</a></p>
</body>
</html>
"##运行结果
root@example-org:~> ./send-mail.sh
Trying 11.19.33.68...
Connected to smtp.example.org.
Escape character is '^]'.
220 smtp.example.org ESMTP ready.
250-smtp.example.org Hello smtp.example.org [11.19.33.68]
250-SIZE 52428800
250-PIPELINING
250-STARTTLS
250 HELP
250 OK
+ echo 'RCPT TO:<mail1@example.com>'
+ set +x
250 Accepted
+ echo 'RCPT TO:<mail2@example.org>'
+ set +x
250 Accepted
354 Enter message, ending with "." on a line by itself
250 OK id=1XKiQd-0000I7-2l
Connection closed by foreign host.