SMTPMail question

  • Thread starter Thread starter Guest
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Guest

Hello,
Please forgive this basic question. When sending mail using the SMTPMail
class in System.Web.Mail, how does the mail server know you are allowed to
send mail through it? For example, I used smtp.comcast.net as the Smpt Server
(because that is my internet provider), and it sent the mail fine. How does
this work since you don't supply a username or password? Does it know the
mail is coming from an ip address that has comcast service? I would
appreciate it if someone could explain it to me.
Thanks,
Rob
 
The SMTP protocol doesn't authenticate you based on user name and password.
Instead it can reject relaying based on IP addresses and machine names.
 
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