. How does the mail server detect whether the outbound e-mail is submitted programmatically or manual?

i am using smtp.live.com for sending emails in .net application. Live SMTP temporarily blocks the account after s开发者_开发知识库ending few e-mails through the service

How does the mail server detect whether the outbound e-mail is submitted programmatically or manual?

It doesn't.

What probably happens is that you are sending many emails in a very short time period causing an automatic throttling setup by live.com.

I suggest reading the email terms and conditions.

Maybe its is not the way you submit but the times you send messages. The sending frequency. Some servers block the account if you try to send too many messages in a short time.