EMAIL

[P1]

Thank You Tedd!!

Regards,  P1  :8)

[P1]

Let take an example of a bad SMTP server address in a e-mail from Outlook.

Send an e-mail to NOSPAM@NOSPAM.COM

Outlook will take it and send it via POP3 to the local server.  And you will not get any errors from Outlook.

When the local server tries to forward it via SMTP, it will find the error and write you a nice e-mail back saying to the effect, that e-mail server does not exist, the next time you get mail.

More later.

Regards,  P1  :8)

[tenkey]

Hmmm. That POP3 RFC link doesn't show a protocol for sending e-mail from a client, only receiving from the server. The document is fairly short, so am I blind?

[Robert Collins]

Let take an example of a bad SMTP server address in a e-mail from Outlook.

Send an e-mail to NOSPAM@NOSPAM.COM

Outlook will take it and send it via POP3 to the local server.  And you will not get any errors from Outlook.

When the local server tries to forward it via SMTP, it will find the error and write you a nice e-mail back saying to the effect, that e-mail server does not exist, the next time you get mail.

More later. 

Regards,  P1  :8)

Again, I ask what is this local server? You say that Outlook will send it to the local server. I see no local server on my PC. I see only Outlook which is a client. From my testing, I saw that Outlook sends email to "smtp.email.msn.com" but that server is not on my machine, it is on the Microsoft domain.

[Tedd]

Hmmm. That POP3 RFC link doesn't show a protocol for sending e-mail from a client, only receiving from the server. The document is fairly short, so am I blind?

Blind? Nope, not quite :wink
POP3 is ONLY for receiving emails (by the client, from the server), not sending.
SMPT is for sending (and not receiving).

[P1]

Robert,

I own you an apology!  You are right that a "Internet Account" setup on Outlook and other clients, do use a Local SMTP server to relay out the message from the client. 

I was wrong and you right.  I apologize for confusing you over the e-mail flow in this transaction type. 

But the POP3 local server is configured ( or should be ) to be the local STMP gateway/relay for the POP3 client.

But the previous example is correct in that the Local server is the device that forwards the e-mail to all recipients of the message.  The client only delivers the message to the relay server, not the the destination clients.

I will be doing some testing tonight to verify the above.

In my early POP3 account days, I had used the same server for the inbound and outbound mail flow.  And in all the other E-mail servers since then as well.  But it was Groupwise & Exchange since then.

Regards,  P1  :8)

[Tedd]

A brief explanation of how it (generally) works..

I want to send an email from myself@my.email.com to myfriend@some.other.email.com

So first I write my email and then use SMTP on port 25 to give the email to the smtp server at my.email.com

Upon receiving this email, the mailhost for my.email.com will recognize that the destination is not local, and so will forward the email on to (possibly indirectly through several other servers) eventually reach some.other.email.com

At some.other.email.com, the mailhost will recognize that the destination is a local account, and so hold on to the email :wink

Then, myfriend wants to read their email, so they log in to their account on some.other.email.com and use POP3  on port 110 to ask the server if there is any email for the myfriend account. And there is! So the email is received and read and so on..


(Equally, if myfriend should reply, they would send with smtp, and I would receive that reply with pop3)

[AeroASM]

Again, I ask what is this local server? You say that Outlook will send it to the local server. I see no local server on my PC. I see only Outlook which is a client. From my testing, I saw that Outlook sends email to "smtp.email.msn.com" but that server is not on my machine, it is on the Microsoft domain.

When they say "local", they do not mean on your machine but the one in your vicinity (fairly loose definition of vicinity though). They mean local as in your ISP's email server, as opposed to some other email server.

A normal mail server has two sockets:

One socket to listen on port 110 protocol SMTP to wait for any messages, whether they come from a PC or another server, and relay them on to another SMTP server.

Another socket to listen on port 25 protocol POP3 to wait for a connection from a PC, to request new mail to be downloaded.

A mail client has one socket, to do two things:

One socket to connect to the SMTP server to send mail
Another socket to connect to the POP3 server to receive mail.

However what you want to do is set up an alias or mail forwarding service, such that any mail addressed to your domain name goes to your home email address. in this case you don't need a pop3 server, because your domain name server will have no clients. You need an SMTP server which just relays on messages from other servers, with one exception. When an SMTP receives a message which belongs to one of its clients it will store it in a server-side mailbox to be collected later on by the client (using POP3). When your server receives a message which belongs to one of its own clients, it needs to re-address it to your home email, then send it on.

(please can someone check this, because I have no prior knowledge and have pieced this together from the earlier posts in this thread)

[Tedd]

One socket to listen on port 110 protocol SMTP to wait for any messages, whether they come from a PC or another server, and relay them on to another SMTP server.

Another socket to listen on port 25 protocol POP3 to wait for a connection from a PC, to request new mail to be downloaded.

pedanticism:
smtp = port 25
pop3 = port 100

Otherwise it sounds correct.

[AeroASM]

One socket to listen on port 110 protocol SMTP to wait for any messages, whether they come from a PC or another server, and relay them on to another SMTP server.

Another socket to listen on port 25 protocol POP3 to wait for a connection from a PC, to request new mail to be downloaded.

pedanticism:
smtp = port 25
pop3 = port 100

Otherwise it sounds correct.

actually its pedantry, to be pedantic ;)  :U

[Tedd]

actually its pedantry, to be pedantic ;)  :U

Actually, it's "smartass" :lol