Thank you for reply.I have indeed set up SASL authentication as you describe and the actual authentication (which occurs at each connection to the remote SMTP server) works fine.
The problems are :1) My ISP doesn't like *empty* AUTH=<> in the "MAIL FROM:" field of the envelope. They *do* accept any non empty address as well as no AUTH option.
As this is hardcoded into postfix I can see no solution to this other than a patch
2) The MAIL FROM: address in the *envelope* has to be associated with the same account as the username,password pair given to SASL. The from address in the *header* can be something else.
This could be fixed by address rewriting but I can't see how (in postfix 2.1) to rewrite the envelope sender address without modifying the header sender (as I would like the recipient to see the real sender). It seems postfix 2.3 can do this but it also supports per sender SASL authentication which is probably simpler.
Roberto C. Sanchez wrote:
Here is what I have done when I had an ISP that required SMTP AUTH:
Snip
# cat /etc/postfix/sasl_passwd -Roberto
Regards, Martin