>Hi everybody,
>
>I need an understanding of conceptual difference between SMTP email and email sent to Exchange Server?
>
>Here is why. My application is sending email messages to SMTP (using WWIPSTUFF). Everything worked perfectly until customer started to block SMTP mail from desktop computers. They say they now allow only email to Exchange Server from desktops. How are the two different? What tools do I need to send email from VFP application to Exchange Server?
>
>Thank you in advance for any help.

SMTP is the standard internet mail sending protocol. Exchange as well as most other Email servers understands it.

Exchange also has its own native protocols that Exchange clients can use to send mail.

One way companies try to reduce the abilities of spammers to send spam through their mail servers is to block SMTP mail. Generally they block SMTP mail coming from outside their network.

Some companies block ALL SMTP mail, allowing only Exchange clients to send mail. This works fine unless you need other systems to send mail.

You can send mail via Outlook using outlook automation, which is a pain and can be problematic.

I'd suggest asking your client to allow SMTP mail from addresses in their IP address space which is reasonably safe on a well run network. This is very easy to do in Exchange (takes a minute or 2 to do). SMTP mail will still be blocked from outside addresses which is the main intent anyway.

If they won't do that, tell them it will cost them $$ to get around it, and start looking at Outlook automation.