Getting servers for sending mail via SMTP

[intergerous]

I have looked in this article:

http://www.codeguru.com/Cpp/I-N/inte...icle.php/c6177

It shows how to send mail via SMTP.
However, in order to send email I need to connect to a server via mail.connect().
My question is, how do I get the available server on the computer the program runs (the client)?

Thanks in advance.

[tmecham]

Well, how do you know who the message is coming from? Either it is predefined, in which case you should already know the SMTP server or you need to get a "From" address from the user at which time you would need to get the SMTP connect info from the user as well.

[Marc G]

[ moved thread ]

[j0nas]

It can be done.

You should extract the FQDN (domain name) of the recipient mail address, and then lookup its MX record (in DNS). The MX record contains a hostname which is resolved into an IP for the recipient's mail server (SMTP).

NOTE: For security reasons, most SMTP servers will perform a reverse DNS lookup of the calling IP address and then use the FQDN to lookup the MX. If the calling IP doesn't have a MX record, it will most likely reject it.