Here an explanation for those who have no clue about SMTP: Mail Client ------> My Mail Provider ------> Recipient's Mail Provider SMTP SMTP The "Mail Client" usually uses a dial up IP address. This is often an IP address which is on a Black List. Therefore the "Recipient's Mail Provider" would not accept it directly. The "Mail Client" therefore sends the mail to the "My Mail Provider". This host can authentificate the mail: the mail must be from the domain the "My Mail Provider" administrates and the E-Mail address must exist. A spammer cannot use "My Mail Provider" as an open relay because he has not a valid account on this server. The "My Mail Provider" sends the mail to "Recipient's Mail Provider". The "Recipient's Mail Provider" accepts the mail because the "My Mail Provider" has a fixed IP address and this IP address is not an a Black List. For those who still do not understand why it is not a good idea for Coditel to relay their customer's non xyz(a)coditel.lu addresses, here's the explanation: Unlike "My Mail Provider" Coditels relay could not ensure that I did not fake my From field. Infact I could even use a non existent address (as long the domain exists in the DNS). Coditel would essentially be an open relay reserved for their own customers. The From field could be anything a worm would find in a address database, Coditel's mail server could not filter it. Everybody understands? I mean if you understand the SMTP protocol and the fact I do not want to change my own E-Mail address everytime I change a dialup service, than you will see that I use my dialup access in a *sensible* way. And yes: The engineless car is waiting for you ;-)))))) Patrick Kaell