> <http://www.faqs.org/rfcs/rfc2822.html>RFC<http://www.faqs.org/rfcs/rfc2822.html> > 2822 seems to say both are optional, but I'm not clear on the > differences, so I have two questions...
The difference is that the Reply-To: is created by the MUA within the message data (headers/body), while the Return-Path: is taken from the pre-data MAIL FROM (envelope sender), but inserted within the message data by the MTA. > Question #1: I'm thinking maybe my database should trap for both of > these headers and if there's data in one use it for my reply else > use the 'from' address. Is that reasonable? No, you should use only the Reply-To:, then the From:, in any kind of customer-oriented database. The Return-Path: is intended for use by the underlying SMTP transport (for DSNs/bounces). Reply-To: and From: are for replies to humans by humans. > Question #2: for outgoing messages is it best to use the Return-Path > header or the Reply-To? Isn't that the same question? The Reply-To: specifies a human processing replies on behalf of the From: human. The From: human is used if not overridden by the Reply-To:. While in the vast number of cases you will see cosmetic overlaps among these three headers, you should respect their separate functions and not attempt to reply to a message sent without either human header. (Note that some intermediate MTAs will prepend From: headers -- copied from the envelope sender -- in the event that they are not originally present. Even if the original omission is detected, you can still use send human replies, as at least the message has been "massaged" into good form before it reaches you.) --Sandy ------------------------------------ Sanford Whiteman, Chief Technologist Broadleaf Systems, a division of Cypress Integrated Systems, Inc. e-mail: [EMAIL PROTECTED] SpamAssassin plugs into Declude! http://www.imprimia.com/products/software/freeutils/SPAMC32/download/release/ Defuse Dictionary Attacks: Turn Exchange or IMail mailboxes into IMail Aliases! http://www.imprimia.com/products/software/freeutils/exchange2aliases/download/release/ http://www.imprimia.com/products/software/freeutils/ldap2aliases/download/release/ To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
