How to Outlook send a E-mail

J

jgasparelli

When I send a email to [email protected] how to Outllok check or validated
this email address. Look for a cache file (.nk2) and validated? I need know
how to works outlook before send to a smtop server. Could you help me? I
appreciate
JGG
 
V

VanguardLH

jgasparelli said:
When I send a email to [email protected] how to Outllok check or validated
this email address. Look for a cache file (.nk2) and validated? I need know
how to works outlook before send to a smtop server. Could you help me? I
appreciate
JGG
Click to expand...

The only way you can find out if a domain has a particular username
defined for an e-mail account there is to send an e-mail there.

If you know how to use telnet, and if the SMTP server doesn't require
SSL connects, and if you know the SMTP commands, you could start to send
an e-mail but then abort. You would telnet to their SMTP server, enter
the commands to start sending a message but then not send one. That you
got an +OK status back from their server when you specified the
recipient means that receiving mail host will accept e-mails to that
username. The VERIFY command is not supported by many SMTP mail hosts
as it represents overhead to identify a username when an e-mail may not
be sent (and the purpose of the mail host is to send/receive mail, not
waste time identifying their users), plus it can be abused by spammers
digging with repeated VERIFY commands to see which ones are returned as
valid and then send spam only to those valid recipients. If you get a
bad status back from the RCPT-TO command then you know that username
isn't defined there. However, there are misconfigured SMTP mail hosts
that will accept an e-mail before checking if it is deliverable, accept
the e-mail, and then find it is not deliverable (and send back a
non-delivery report e-mail). There are also mail hosts that have a
catch-all account that will accept e-mail with any username. Whether
you use a valid or invalid username, the catchall account accepts all
mails so you won't know if you used a correct e-mail address.

There is no way to validate an e-mail address other than to ask the
receiving SMTP mail host. Rather than do a manual telnet session, there
are utilities to send the SMTP commands and check status to validate a
username. You can Google for those yourself.

Simple Mail Transfer Protocol
ftp://ftp.rfc-editor.org/in-notes/rfc2821.txt

So just send the e-mail. If you get back an NDR (non-delivery report)
then you know the receiving mail host claims there is no such user
there. If you don't get back an NDR, you don't know if it went into a
catch-all account, it vaporized inside their domain (the receiving mail
host accepted the e-mail but never put it into the recipient's mailbox),
it ran afoul of blacklists (which are exercised before touching the
recipient's mailbox) but they didn't send back an NDR, it's sitting in a
Spam folder so the recipient doesn't see it in their Inbox, or other
reasons why the recipient never sees your message. If you want to know
that they got your e-mail, send them a confirmation e-mail asking that
they reply to know that you reached them.
 
J

jgasparelli

Thank you VanguardLH, May be because my english is very poor, I try to
understand how to outlook works before send a email.
When i put a smtp address on "TO", how checks my smtp address:
look for nk2, look for my domain to resolve with active directory, or
directally send a email to exchange/smtpserver? Just I try to understant this
concept.
Sorry if my english is very poor.
regards
jansen
 
V

VanguardLH

jgasparelli said:
I try to understand how to outlook works before send a email. When i
put a smtp address on "TO", how checks my smtp address: ...
Click to expand...

Your e-mail address? Or the recipient's e-mail address?

There is no validation on your e-mail address. It is not used when
sending e-mails. You can specify any e-mail address you want in your
e-mail client which means it could be any string. It could be an
invalidly syntaxed e-mail address, or it might be a validly syntaxed
e-mail address, or it could be your e-mail address, or it could be
someone else's e-mail address, or a bogus e-mail address. It is DATA
inserted into your message and never used when sending your messages.

As pointed out, the only entity that can validate the recipient's e-mail
address is the recipient's mail server. Read my prior post on how that
is accomplished.
... look for nk2, ...
Click to expand...

That is a list of e-mail addresses that you entered in the input fields
in the new-mail window. There is no validation there. It is whatever
you entered. If you entered an invalid e-mail address then it gets
saved into this nickname file. If you entered an invalidly syntaxed
e-mail address, it still gets saved into the nickname file. The
nickname file contains whatever you entered in the input field. It is a
history list, and nothing in it needs to be valid nor has any entry
within it been validated.
... look for my domain to resolve with active directory, ...
Click to expand...

If you are in a domain, you don't need to validate your own e-mail
address nor do you need to look for your own domain. Your sending mail
server in your corporate network only knows about e-mail addresses for
its own users (i.e., the employees within the same company) because
everyone is sharing the same mail server. When sending e-mails outside
that domain, again only the receiving mail server knows what usernames
are defined there, so reread my prior post on how that works.
... directally send a email to exchange/smtpserver? ...
Click to expand...

Yep, that's the only way to find out from the receiving mail server if a
username is defined there. If you are asking about the Exchange server
used at your company, the GAL (Global Address Lookup) has already been
updated for the company's employees. Since it is the receiving mail
host when you send your message (it is both the sending and receiving
mail host) then it knows what usernames are valid there. When sending
messages outside your company, their Exchange server doesn't know
anything about users defined at other domains so it will also have to go
through the same process of sending an e-mail to the other domain to
find out if that username is defined there.
... Just I try to understant this concept. Sorry if my english is very
poor.
Click to expand...

Besides reading through the RFC for SMTP (a link was already provided),
you could also Google search on tutorials, like:

http://www.google.com/search?q=+smtp++tutorial
http://www.google.com/search?q="how+email+works"

I have no idea just where is your comfort level with technology. SMTP
can be complicated to understand (and then seems simple afterward) but
it also involves other concepts, like DNS and accessing MX records from
the receiving domain to find out which mail host to use to send e-mails.
 
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