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January 03, 2005
The growth of SMTP capabilities in Exchange
Chapter 7, "Routing, Transport, and SMTP," got sent off to our editor (hi, Robbie!) last night. This chapter was a departure for me because it was one I wrote myself beginning to end, instead of taking a few recipes here and there. I'd volunteered to write this chapter because it is, at heart, about SMTP, and with my years of administering UNIX mail systems, I have a fairly good handle on SMTP; my clearest handle on Exchange is coming from the SMTP side and working inward.
As I was researching several of the recipes for this chapter, I became aware that there was a lack of what was (to me) painfully obvious documentation on Exchange. One of the things that I needed to know was what SMTP and Extended SMTP (ESMTP) keywords and verbs the various versions of Exchange supported. I could find bits and pieces of this information all over the place, but nobody seemed to have a nice side-by-side comparison chart.
The obvious answer to that was to compile one. Since I didn't end up using it in any of the recipes directly (although it may yet end up somewhere in the book), I figured I'd share what I compiled. Please, feel free to let me know if you find errors or omissions; I have no ego invested in this.
Without further ado...
| ESMTP keyword or verb | 5.5 | 2000 | 2003 | Notes |
| 8BITMIME | X | X | Permits 8-bit message bodies | |
| ATRN | X | X | Authenticated TURN; requires SMTP AUTH | |
| AUTH GSSAPI | X | X | Kerberos authentication | |
| AUTH LOGIN | X | X | X | Basic authentication |
| AUTH NTLM | X | X | NTLM (IWA) authentication | |
| BINARYMIME | X | X | Requires CHUNKING; permits unencoded 8-bit data transfer | |
| CHUNKING | X | X | Streamed-mode data transfer | |
| DSN | X | X | X | Delivery Status Notification |
| ENHANCEDSTATUSCODES | X | X | ESMTP enhanced status codes | |
| ETRN | X | X | X | Extended TURN; requires DNS MX entries |
| PIPELINING | X | X | Performance enhancement | |
| SIZE | X | X | X | Maximum message size advertisement |
| STARTTLS | X | X | X | Draft TLS spec; start SSL for rest of session |
| TLS | X | X | X | Final TLS spec; start SSL for rest of session |
| TURN | X | X | Server delivers mail queued up for client | |
| VRFY | X | X | Verify recipients | |
| XEXCH50 | X | X | X | Exchange specific extended message properties |
| X-EXPS GSSAPI | X | X | Exchange org-specific authentication using Kerberos | |
| X-EXPS LOGIN | X | X | Exchange org-specific authentication using basic authentication | |
| X-EXPS NTLM | X | X | Exchange org-specific authentication using NTLM | |
| X-LINK2STATE | X | X | Cross-routing group link status updates |
Posted by Devin Ganger at January 3, 2005 02:24 PM