On Tue, Jul 15, 2008 at 8:16 PM, Steve Poe <[EMAIL PROTECTED]> wrote: > I am new to email servers, so pardon my ignorance. > > The small company I work for has an email server where they want > to create an approved/whitelist for emails coming from the outside. For > example, > I email [EMAIL PROTECTED] the abc.com mailserver does not see my email > address in approved list for the user account and/or as a company-wide > contact list, so the abc.com mail server sends a reply to me to confirm I > sent > the email that I *really* wanted to send the email to [EMAIL PROTECTED] > Meanwhile, > John receives my email, after confirmation of my response, then he adds me > to his personal contact/approved list. The mail administrator found out > that > I am > a new client of abc.com so I am added to the company-wide approved list. > > We are running Courier 0.53 on Centos Linux 4.4 > > > Is this possible?
It sure is possible and there are projects in the opensource world and products in the proprietary world which you can use to do exactly this. Consider this though? What if I use the exact same system and you email me? I'll issue you a challenge, your email system will respond to mine with a challenge, to which I'll respond to you with a challenge for infinity, without the mail getting delivered. Simply put, if everyone used this scheme, nobody would get any mail, and if you use it, you're immediately not going to get mail to or from some other organisation that does use it nor will they get email from you. Want to buy airline tickets? Airline emails you your eticket, your email system responds to them with a challenge "did you really send this to me", the automated airline ticketing system won't respond, you won't get your airline ticket. Even if you whitelist the airline, you can't be sure they wont be delivering the eticket through a content distribution partner which won't be in your whitelist. Ironic that you questioned this today, as one of my email customers is a subsiduary of a French multinational who run such a system. One of my guys went on holidays and put up a vacation notice. I only know he's on vacation because of the postmaster emails I've been getting saying that his vacation notice was undeliverable. I just consider such a system bad manners because you're shoving your spam cleaning burden onto me, do it yourself. Its bad bad form, don't go there, and talk your customer out of it. Blacklisting will reclaim all mailsystems from the spam burden, and add spamassin into the mix to pick up the slack and you're home and dry. HTH, -Enda. ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ courier-users mailing list [email protected] Unsubscribe: https://lists.sourceforge.net/lists/listinfo/courier-users
