On 06/06/2011 06:47 PM, Raj Mathur (राज माथुर) wrote:
I believe you're confused between auth on your server and auth to the ISP. Auth on your server we can afford to ignore -- you've clearly said it's IP based, and that's the end of it.
On the other hand, it's highly unlikely that your server will be authenticating to the ISP as a different user for each sender. Typically mail servers use one identity to talk to other mail servers. Your ISP would be letting your server relay through it on one of the following conditions:
Thanks to all those who responded. Raj, could you tell from my main.cf settings if the smtp auth from postfix to the ISP is happening with only the first account in the sasl_password file or does it happen with each user that is listed one below the other? What you mention must be happening, there is one account getting authenticated for every mail relayed from postfix. That is why users that do not exist get their mails going through. How do I ensure that postfix sends the respective username:password for every mail according to the sender id? So if the user does not exist, there should be no auth happening.