cisco prime infrastructure 3.10的版本，在 “”Administration / Settings / System Settings / Mail Server Configuration”中配置了SMTP服务器，然后点击“Test”，但是收不到测试邮件。
PI会有alarm提示：
System with IP Address '192.168.99.210' failed to send email .This may be due to possible SMTP misconfiguration or network issues.已做过的排查有：
1.检查SMTP服务器是正常的，因为备份服务器用同一个SMTP地址， 备份服务器的邮件通知是工作的。
2.PI服务器的shell中telnet到smtp的25端口是开放的
jd-s1-cisco-pi-01/admin# telnet smtp.XXX.XXX.com port 25
Trying 119.xxx.xxx.199...
Connected to smtp.xxx.xxx.com.
Escape character is '^]'.
220 smtp.xxx.com Esmtp xxx Mail Server
quit
3.更换25或者465/SSL端口，not work
4. 在PI的shell里关闭firewall，not work
ade # systemctl stop firewall
==== AUTHENTICATING FOR org.freedesktop.systemd1.manage-units ===
Authentication is required to manage system services or units.
Authenticating as: root
Password:
==== AUTHENTICATION COMPLETE ===
ade # systemctl status firewall
● firewall.service - CARS firewall
Loaded: loaded (/usr/lib/systemd/system/firewall.service; enabled; vendor preset: disabled)
Active: inactive (dead) since Mon 2024-03-25 16:03:12 CST; 2s ago
Process: 24252 ExecStop=/opt/system/bin/firewall_service.sh stop (code=exited, status=0/SUCCESS)
Main PID: 940 (code=exited, status=0/SUCCESS)
5.使用hMailServer搭建内网的SMTP中转服务器，让PI使用这个内网IP地址，但是点test会提示PI无法访问中转服务器的25端口；但同时我用PortCheck测试内网地址的25端口是正常的：
能想的方法几乎都试过了，还是不行，有没有大佬知道怎么搞。
