Help Me!

Hi Everyone!

I am confused on how SMTP works on Internet. I have just gone through a
book explaining SMTP protocol. According to book when somebody say A
wants to send a mail to B it connects to SMTP server on receiver's site
and submits the mail to the server using SMTP command like:

HELO

MAIL FROM: xyz@abc.com
RCPT TO: pqr@ijk.com
.....
.....
.....
QUIT

The SMTP server locates the mailbox of receiver (if exists and stores
the mail there). So far so good. But this description does not tell
that what happens when the receiver SMTP server is not the SMTP server
where the mailbox of pqr@ijk.com is. For example when I have to send a
mail to somebody@somewhere.com I connect to the SMTP server run by my
email provider e.g. mail.icmail.net and submit the email to it. Now how
does icmail.net figures out where to forward the mail i.e. how it finds
the SMTP server of somebody@somewhere.com and sends the mail to it.
Where is the information about the server i.e. its name and the port
(if not default 25)?

Re: Help Me!

This is a MIME GnuPG-signed message. If you see this text, it means that
your E-mail or Usenet software does not support MIME signed messages.

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amitkumarch@gmail.com writes:

> HELO
>
> MAIL FROM: xyz@abc.com
> RCPT TO: pqr@ijk.com

Wrong. Both addresses must be surrounded by "<" and ">" characters.

> does icmail.net figures out where to forward the mail i.e. how it finds
> the SMTP server of somebody@somewhere.com and sends the mail to it.
> Where is the information about the server i.e. its name and the port
> (if not default 25)?

The receipient's domain is looked up via DNS. The mail server queries for
DNS MX records. If no MX records exist, the mail server will query for DNS
A (or AAAA) records.



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Re: Help Me!

Thanks.
But I forgot one thing in my question. Sorry for a trouble again.
How does the server @icmail.net will resove the issue of SMTP
authorization. Some SMTP servers allow mail to be uploaded only after
SMTP authorization. It requires icmail.net to authorize to ijl.com 's
server before forwarding my mail.

Re: Help Me!

This is a MIME GnuPG-signed message. If you see this text, it means that
your E-mail or Usenet software does not support MIME signed messages.

--=_mimegpg-commodore.email-scan.com-17400-1109635333-0007
Content-Type: text/plain; format=flowed; charset="US-ASCII"
Content-Disposition: inline
Content-Transfer-Encoding: 7bit

amitkumarch@gmail.com writes:

> Thanks.
> But I forgot one thing in my question. Sorry for a trouble again.
> How does the server @icmail.net will resove the issue of SMTP
> authorization. Some SMTP servers allow mail to be uploaded only after
> SMTP authorization. It requires icmail.net to authorize to ijl.com 's
> server before forwarding my mail.

No, it doesn't. Some SMTP servers require authorization only if they are
used to send outgoing mail, by the organization's customers or users. To
send outgoing mail the user must provide a valid userid and password that
the mail server can validate.

It is possible that the same SMTP server can also accept incoming mail for
the organization. When the receipient's address specifies a local mailbox,
no SMTP authentication is required. SMTP authentication is required only if
the receipient's address is not a local mailbox -- the connecting SMTP
client is a user/customer sending outgoing mail.



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