Talk:Simple Mail Transfer Protocol

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[edit] Commands and Error Codes List

Do we really need the commands and error codes? Wikipedia is not a general knowledgebase. --Xcali 04:18, 14 Jun 2005 (UTC)

It's useful, and not overly long. I say leave it.
Beska 18:17, 15 Jun 2005 (UTC)
I'm for leaving the details in.
~ender 2005-10-24 16:24:MST

Not a general knowledgebase? What is it then?

It's an encyclopedia. Paper Encyclopedias don't include some General Info, neither does the wiki

Wikipedia:What_wikipedia_is_not is a good reference. That being said, I think the command and error codes should definately be kept. They are an important part of SMTP, and the descriptions are useful and interesting. ArrowmanCoder 14:39, 17 August 2005 (UTC)

[edit] Alternatives

Aren't alternatives being developed for SMTP? Protocols with more security and are able to handle large attachments more efficiently?--ShaunMacPherson 09:54, 3 October 2005 (UTC)

Yes, there's at least one: Internet Mail 2000.
~ender 2005-10-24 16:23:MST

[edit] WindowsNetworking.com link

I disagree about the usefulness of this link: Understanding SMTP Protocol. The article is more useful than the link, and for those who want more information, other listed links are better. Also that link is definitely self-promotional spam, as seen here. Aapo Laitinen 17:16, 21 October 2005 (UTC)

[edit] History?

So who wrote the protocol, how did it get implemented, etc, etc... I'd like some of the history, and not just dry technical details (which are good to have)
~ender 2005-10-24 16:23:MST

I've split the WP:LEAD section, the content starts now with "history". I've also added a list of main "developers" (authors of relevant RFCs ). Omniplex 01:55, 25 February 2006 (UTC)

[edit] Proposed merge

done. Omniplex 07:36, 4 March 2006 (UTC)

[edit] ESMTP SIZE

Shouldn't that go to the ESMTP article? I'd like to keep this for the basics without EHLO, and there's still a lot to say about MX priorities, error codes, etc. Nevertheless I've removed the old (?) {{technical}} template here, IMHO the article isn't too bad. -- Omniplex 20:06, 10 April 2006 (UTC)

I thought this would be "simple"  :)
I've no strong feelings about you moving the example if you wish — in the small picture you're correct. But I suggest that the articles collectively have serious problems of incorrect emphasis, ambiguation, and pedagogy.
The emphasis problem as I read ESMTP, "basics without EHLO" no longer exist in the RFC compliant universe ('Support for the EHLO command in servers was made a "MUST,"...'). HELOs aren't basics because they are tolerated in deprecated fallback only after a client first tries EHLO. If HELOs have some advantage for a beginning user doing manual testing or sending, that belongs in a tips-&-tricks focus.
This SIZE example and failure of Wikipedia to help actually happened to me. I originally looked for a solution here (at "Simple Mail Transfer Protocol"), didn't find it, and researched it. Since the research was inherently difficult, I plugged it in back here where I originally expected to find it.
Why did I expect it here? The ambiguation problem is that "Simple Mail Transfer Protocol" is actually a system and "SMTP" is a deprecated protocol, but these terms are used interchangeably in the field. For example, a large number of servers are named 'smtp.example.com', yet they mostly aren't and should not be SMTP protocol. For this reason I'd vote no to the name change as "SMTP", though I might compromise on "SMTP Protocol (Deprecated)"
There are also the specific pedagogy problems of teaching things in slices that are too small to be immediately helpful (separate SMTP & ESMTP pages), or too simplified to recognize in the field. For latter analogy, Old MacDonald's Farm leaves children clueless about agribusiness.
Seems to me that the pages should be combined and structured more or less like:
_Simple Mail Transfer Protocol / ESMTP / SMTP_" {however Wikified}
  • Disambiguation
  • Introduction {to include the first two paragraphs of current "History"}
  • ESMTP Protocol
- example(s) {focused for intermediate users}
  • SMTP Protocol (Deprecated) {what to do when EHLO fails}
- example(s)
  • SMTP Security and Spamming
  • MX Records {focused for advanced users and admin students}
  • History
- developers
  • Related RFCs
Btw, thanks for checking RFC 1870 for being current, and the link to RfC on how to check.

Milo 08:04, 11 April 2006 (UTC)

Okay, let's see what happens. Officially STD 10 + STD 3 are still the full Internet standards, and 2821 is "only" a proposed standard, but as you said that's not exactly related to the reality outside of the IETF. Merging it all would be a bad idea, some extensions like AUTH (ESMTPA + ESMTPS + ESMTPSA) deserve a separate article, and 2476bis (SUBMIT) got now a number, it's at "draft standard" (better than 2821). SIZE+HELP+PIPELINING are pretty basic, having them here or there is both okay at the moment. If we ever reach a point where the complete "mail architecture" is discussed here we could move the extensions to ESMTP - because then SMTP would be a rather long article. No issue at the moment.
(A recent "rv" let me see this talk page in my watchlist, I missed your old comment, sorry). -- Omniplex 02:08, 11 May 2006 (UTC)

[edit] So let me get this straight

So e-mail servers like Rogers Yahoo and Hotmail use SMTP as a base, then transfer the message to your mailbox? 70.25.138.179 20:35, 21 June 2006 (UTC)

Yes. When Hotmail "talks" with Yahoo, sending mails from Hotmail users to Yahoo users, then the protocol of this "talk" is SMTP (or rather ESMTP as explained above and in the article, SMTP with some extensions). -- Omniplex 20:48, 21 June 2006 (UTC)

Alright then. Maybe this should be clarified in the article. What about communication within an e-mail server, would that just be internal, or would that use ESMTP? One more thing, how are HTML messages transferred? Thanks. 70.25.138.179 21:25, 21 June 2006 (UTC)

Internally (e.g. MX to MDA) they either use also (E)SMTP or LMTP (local MTP). I can't tell you more about the latter, some simplifications because it knows where mail has to go to, no need to lookup MX records. For different mail formats see MIME. -- Omniplex 21:48, 21 June 2006 (UTC)

Thanks! I didn't really expect someone to reply so soon on a subject like this! 70.25.138.179 22:03, 21 June 2006 (UTC)

Omniplex is clearly more familiar with the details, but depending on your tech level, I've written a more general explanation in a new section below, that you or others may find useful. Milo 00:51, 22 June 2006 (UTC)

[edit] Deep fast dive into internal email serving

...communication within an e-mail server, would that just be internal, or would that use ESMTP? ... how are HTML messages transferred?

Both, I'd say, and HTML is handled the same as other messages.

  • The e-mail server viewed at its input and its output handles messages according the ESMTP (or other) protocol. Internally it communicates using a black box process that is analogous to ESMTP, yet is somewhat different for every brand of program.
  • In general, the email server's black box is a set of interacting executable programs typically coded in C language. C program coding implements memory data spaces known as buffers, for transferring character-coded messages "within an e-mail server", from one buffer to another (loosely called "buffering").
  • For example, when using the classic ASCII character-code, the letter "A" is represented in 8 memory bits (one byte) by a binary "0100-0001", meaning that "1" memory bit cells have a slightly higher voltage electrical charge than do the "0" cells.
  • To communicate internally, the C program repeatedly instructs the computer hardware's CPU to copy the voltage of bits from buffer 1, write those bits to buffer 2, and then delete those bits from buffer 1 to make room for the next group of incoming message bits. This is useful because incoming messages can be sorted for delivery by reading the user@address.tld and writing messages with recognized addresses to buffers 2, 3, and 4, that eventually get written to local mailbox X, neighboring computer Y, and external network Z.
  • The ESMTP protocol is implemented when buffering the formatting between characters, lines, and message blocks, but ESMTP is more-or-less ignored while ASCII-coded bits within the message are buffered.
  • HTML is just another language dialect using ASCII (or now Unicode) character codes. ESMTP protocol doesn't care whether the message's dialect/language is English, Spanish, or HTML -- every message text bit is buffered in the same way. If your desktop email program is too ancient to read HTML, you will see an HTML message with many exposed codes that are hard to read, just as Spanish is hard for an English speaker to read. Milo 00:51, 22 June 2006 (UTC)


Ah, I see. So it just transfers the basic text of the message, and the HTML is interpreted later. Thanks!--70.25.138.179 02:37, 25 June 2006 (UTC)

[edit] Possible Copyright Violation?

Happened to google similar text and notice there's a bunch of word for word text at:

http://www.kerberosworld.com/Simp-to-Socc/smtp_server-sntp_server.php

That matches this entry. It's of course possible wikipedia is the authoritative source, but figured I'd mention it here just in case. —The preceding unsigned comment was added by 68.226.4.50 (talk • contribs).

That website appears to be one of many sites that simply copies wikipedia articles, adds a lot of ads and hopes to make money off it. Thanks for checking though. Wrs1864 14:26, 12 December 2006 (UTC)
Yeah, I recognize some of the stuff I wrote in there. Is Wikipedia aware of this particular website? Should we put it on a list somewhere of websites violating Wikipedia's license, or whatever is generally done? --Steven Fisher 19:23, 12 December 2006 (UTC)
What in the hell they violate? Wikipedia license is completely commercial friendly. You can take stuff, and sell it. Or put advertisement and show it. Or make money any other way. TestPilot 06:41, 31 December 2006 (UTC)

[edit] typo?

"(Unix to Unix CoPy)" -- really "CoPy"?

That isn't really a typo, the abbreviation "UUCP" does stand for "unix to unix copy" and the capitalization is used to show which letters were used. I think this is in violation of the WP:Manual of style. Wrs1864 13:39, 9 January 2007 (UTC)

[edit] SMTP over SSL

Is it a deliberate omission that there is no mention of SSMTP and port 465? SSMTP is recommended for client to MTA communication whilst MTA to MTA communication remains over regular SMTP. Although TLS/SSL can be used on regular SMTP channels to verify the endpoints using a separate port assists network administrators who can simply reject connections to port 25 to stop spamming from infected machines and help preserve their MTA's good reputation. StevenMcCoy 10:01, 1 February 2007 (UTC)

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