Linux服务器一开防火墙就出来错误Uncaught exception 'phpmailerException' with message 'SMTP Error: Could not connect to SMTP host.'。本地又是好的。

 

Our Service allows you to use your own mail server and client to send outgoing mail even if your ISP blocks SMTP (port 25).

Linux
type telnet smtp1.arin.net 25 (press enter)

if you get back 220 smtp1.arin.net . . . your ISP DOES NOT block port 25

 

最后发现防火墙未将 25端口开完全