Jimemac Posted December 10, 2004 Share Posted December 10, 2004 Ok, I need some answers from all you email server administrators. I recently learned our firewall isn't configured to pass ESMTP or EHLO traffic onto our email server. Which may be a good thing, I can't tell. I have no clue what EHLO or ESMTP is. Can someone point me to a nice FAQ or something about it. I have recently started having trouble receiving email from clients because we are denying EHLO requests on our server. (and apparently their server isn't retryin the connection with HELO) Is it safe to enable it? Which extension are safe to turn on? If I turn on ESMTP and leave all the options off, does that mean that servers will drop the connection rather than retrying w/ HELO? Help! This is all too complicated for me. Oh and a little rant here. The IETF.org site could use a little modernization don't you think, I mean they are the standard for Internet stuff! Thanks for your help all, Jimemac Link to comment Share on other sites More sharing options...
Wazoo Posted December 10, 2004 Share Posted December 10, 2004 I'm thinking that little things like what firewall, what e-mail app, what OS, ..... might mean something to "all those e-mail admin folks" that might jump in with something ... Link to comment Share on other sites More sharing options...
Jimemac Posted December 10, 2004 Author Share Posted December 10, 2004 Thanks for your reply Wazoo. I'm not looking much for specifics on setting my firewall, email server, etc. More an explanation as to what ESMTP is and what may be some advantages/disadvantages to enabling it. I haven't been able to find any comprehensive/easy to read material on it. This is just a learning expedition for me, not a "how do I get this email to go through thing." But in case its absolutely necessary, I'm using Symantec VelociRaptor (I like to call it the CRAPtor), and Exchange 2000 on a Windows 2000 server. Thanks again for any advice! Jime Link to comment Share on other sites More sharing options...
Merlyn Posted December 10, 2004 Share Posted December 10, 2004 ESMTP provides the capability for a client e-mail program to ask a server e-mail program which capabilities it supports and then communicate accordingly. Almost all commercial e-mail servers and clients support ESMTP. ESMTP (Extended Simple Mail Transfer Protocol) specifies extensions to the original protocol for sending e-mail that supports graphics, audio and video files, and text in various national languages. The original Internet protocols for sending e-mail are described in Request for Comments (RFC) 822, Standard for the Format of ARPA Internet Text Messages, and in RFC 821, Simple Mail Transfer Protocol (SMTP). As users began to want to attach various kinds of files to e-mail, the need for additional capabilities arose and resulted in RFC 1869, Extended Simple Mail Transfer Protocol. Link to comment Share on other sites More sharing options...
Wazoo Posted December 10, 2004 Share Posted December 10, 2004 EHLO on an Exchange 2000 server - http://www.google.com/search?as_q=configur...ch=&safe=images ESMTP on Exchange 2000 - http://www.google.com/search?as_q=configur...ch=&safe=images There are instructions, but also other links to places discussing the whys and definitions ... My original response was due to my wondering about a firewall that appeared to involve state and packet inspection (based on your description of blocking certain types of traffic) which imnplied something other than a cheap box, thinking that there'd be some commentary in the docs for that item that would explain thre why part of enabling/disabling of certain "signals" .. as compared to the generic IP and port address assignments. Link to comment Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.