CODEWITHSUNDEEP
smtpimappop3
user287745
user287745

Reputation: 3171

SMTP AND POP3 concepts?

According to the below figures taken from an tcp/ip protocol suit... SMTP AND POP3/IMAP4 are not required if there is one and only one computer attached to the mail server!

If that's true then have does it work make a tcp connection by using telnet and then what?

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Upvotes: 1

Views: 883

Answers (1)

Matt Peddlesden
Matt Peddlesden

Reputation: 520

Your question isn't very clear, I can't quite see where you're drawing this conclusion from.

However, i'll make some assumptions based on what I can see.

If everything is on one server then the two parties using email can simply log in to the server using telnet or remote desktop or something and retrieve email directly from the mail server. E.g. in unix days you'd just type "mail" and have a truly horrendous command line interface to your email - which did NOT use pop3 or anything. I'm not sure if anyone would really do anything this way any more, and on most systems these days even local mail access is done via pop3 or imap just to keep everything standard.

If your clients are remote - i.e. the two UA's in question in figure 20.1 are on the workstations, then they would certainly be using POP3 or IMAP or equivalent.

SMTP is used primarily as a transport between the servers, so if your two parties are on different mail servers then you might use SMTP to get the mail between those two servers. That's not the only way, you could use POP3 retrievers for example, though the norm certainly would be to use SMTP and set the two servers up as MTA's.

I don't quite follow from what you've shown how you've drawn the conclusion that POP3/IMAP are not required - certainly if there's only one server involved them SMTP certainly isn't but the use of POP3 or IMAP would normally still take place.

Of course there are other methods of retrieving email besides POP3 and IMAP such as the way that Exchange does it.

To sum up, the slides you've shown look perfectly fine on their own and potentially out of context, but I have no idea where you've drawn your conclusion from.

Upvotes: 1

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