Sending mail using vb.net

I have developed one application for sending mail using vb.net. for that i'm using system.net.mail namespace; but while sending mail i got one error that is time out. & for avoiding this error i used try catch block but i'm failed to resolve this problem.

Is there any solution on this er开发者_StackOverflow中文版ror?

It seems the problem with the SMTP server, please verify your SMTP settings are valid and also verify firewall settings.

you need open in windows firewall setting I think. What OS you used?if server need this. another I not try yet :D