通过代理服务器发送邮件

Question

I am using a LAN network, which uses a proxy server. In C#, I am trying to develop an application through which I can send E-mails. But from my network, I can't send mail due to this proxy issue. From any other network, not dependent on proxy server, there is no problem to send mail.

I typed in command prompt, telnet smtp.gmail.com 25

and it displays it can't connect to 'smtp.gmail.com'

Answer 1

It sounds like your proxy is explicitly denying the gmail.com domain (if its a corporate network then many do). Can you reach gmail.com in your browser (if you can't this may put up a nasty looking alert from your systems guys).

There are a couple of ways round this:

1. Get smtp.gmail.com, or port 25 to smtp.gmail.com, unblocked on the proxy.
2. Get an smtp relay put in place instaed of using smtp from gmail. There's some info on this here .

Either way, time to go and be nice to your sys admins!