阿里云屏蔽25端口通过465端口发送邮件

买了一台阿里云ECS 准备做nagios监控邮件报警，发现25号端口被屏蔽了，申请开通也失败，然后只能绕过25号端口，走465 ssl端口发邮件了。

步骤如下：

首先请求数字证书

root@PLAY ~]# mkdir -p /root/.certs/ ####创建目录，用来存放证书
[root@PLAY ~]# echo -n | openssl s_client -connect smtp.126.com:465 | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > ~/.certs/126.crt ####向126请求证书

depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert Global Root CA
verify return:1
depth=1 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = GeoTrust RSA CA 2018
verify return:1
depth=0 C = CN, L = Hangzhou, O = "NetEase (Hangzhou) Network Co., Ltd", OU = Mail Dept., CN = *.126.com
verify return:1
DONE

[root@PLAY ~]# certutil -A -n "GeoTrust SSL CA" -t "C,," -d ~/.certs -i ~/.certs/126.crt ####添加一个证书到证书数据库中
[root@PLAY ~]# certutil -A -n "GeoTrust Global CA" -t "C,," -d ~/.certs -i ~/.certs/126.crt ####添加一个证书到证书数据库中
[root@PLAY ~]# certutil -L -d /root/.certs ####列出目录下证书

Certificate Nickname Trust Attributes
SSL,S/MIME,JAR/XPI

GeoTrust SSL CA C,,

然后前往126邮箱打开smtp并获取客户端授权码

网页正上方：设置→POP3/SMTP/IMAP

网页左侧：客户端授权密码

最后配置/etc/mail.rc

set bsdcompat

set from=test_wly@126.com
set smtp=smtps://smtp.126.com:465
set smtp-auth-user=test_wly@126.com
set smtp-auth-password=*********
set smtp-auth=login
set ssl-verify=ignore
set nss-config-dir=/root/.certs

现在发送测试邮件

echo "test mail" | mail -s "nagios report" test_wly@126.com

此时test_wly@126.com收件箱就收到一封刚刚发的邮件了

看起来已经成功了，但是发送完邮件还有报错：证书不被信任，且命令行就此卡住，需要按键才能出现命令提示符

Error in certificate: Peer's certificate issuer is not recognized.

于是

[root@PLAY ~]# cd /root/.certs/
[root@PLAY .certs]# ll
total 80
-rw-r--r-- 1 root root 1793 Jul 6 14:36 126.crt
-rw------- 1 root root 65536 Jul 6 14:37 cert8.db
-rw------- 1 root root 16384 Jul 6 14:37 key3.db
-rw------- 1 root root 16384 Jul 6 14:37 secmod.db
[root@PLAY .certs]# certutil -A -n "GeoTrust SSL CA - G3" -t "Pu,Pu,Pu" -d ./ -i 126.crt
Notice: Trust flag u is set automatically if the private key is present.

问题解决