Ubuntu20.04上安装ssmtp通过SMTP方式发送邮件

系统中使用脚本监控内存和磁盘使用情况，需要用到smtp来发送通知邮件。mailx无法在ubuntu系统上使用，经过尝试可以安装ssmtp来使用SMTP服务向外发送邮件。

1、安装好的Ubuntu20.04中可能已经自带了邮件系统，先删除它们

sudo apt autoremove postfix
sudo apt autoremove sendmail

2、安装我们需要的ssmtp和mailutils

sudo apt install ssmtp mailutils

3、编辑ssmtp的配置文件：

vim /etc/ssmtp/ssmtp.conf

3.1非TLS

我这里是不需要身份验证，使用默认使用25端口，配置如下：

只更新了mailhub=你的SFTP服务器

#
# Config file for sSMTP sendmail
#
# The person who gets all mail for userids < 1000
# Make this empty to disable rewriting.
root=poster# The place where the mail goes. The actual machine name is required no 
# MX records are consulted. Commonly mailhosts are named mail.domain.com
mailhub=smtp.exmail.qq.com# Where will the mail seem to come from?
#rewriteDomain=# The full hostname
hostname=服务名# Are users allowed to set their own From: address?
# YES - Allow the user to specify their own From: address
# NO - Use the system generated From: address
#FromLineOverride=YES

如果需要身份认证，需要添加如下的配置

AuthUser=address@mail.com
AuthPass=邮箱密码

3.2 开启了TLS

如果开启了TLS发送邮件，需要修改配置：

#
# Config file for sSMTP sendmail
#
# The person who gets all mail for userids < 1000
# Make this empty to disable rewriting.
root=poster# The place where the mail goes. The actual machine name is required no 
# MX records are consulted. Commonly mailhosts are named mail.domain.com
mailhub=smtpdm.aliyun.com:465# Where will the mail seem to come from?
#rewriteDomain=# The full hostname
hostname=服务名# Are users allowed to set their own From: address?
# YES - Allow the user to specify their own From: address
# NO - Use the system generated From: address
#FromLineOverride=YESAuthUser=address@mail.com
AuthPass=邮箱密码
UseTLS=Yes
AuthMethod=LOGIN

4、发送邮件测试

# 不带附件发邮件：
echo "This is a email content." | mail -s "Email Title" to@mail.com
# 带附件发送邮件（注意在Ubuntu下附件使用附件参数-A，与Centos中的-a不同，注意大小写）：
echo "This is a email content." | mail -s "Email Title" -A /path/to/test.gz to@mail.com
# 要显示回复邮箱地址，加上-r参数，该邮箱可以为任意指定邮箱：
echo "This is a email content." | mail -s "Email Title" -r from@mail.com to@mail.com
# 指定发件人名字和发件人邮箱地址（与配置中的邮箱地址一致），避免以root@hostname的来显示发件人名字
echo "This is a email content." | mail -s "Email Title" -a "From: Someone <from@mail.com>" to@mail.com

5、问题处理和日志检查

查看发送邮件的日志和记录