Postfix SMTP authentication not working

[jeronimo@mpcnet.com.br (Jeronimo Pellegrini)]

Hello!

I have just installed postfix hre, but I can't get it to authenticate
with my ISP's smarthost.
I've read the documentation, and this is what I did:

In my /etc/postfix/main.cf:

 smtp_sasl_auth_enable = yes
 smtp_sasl_password_maps = hash:/etc/postfix/saslpd
 smtp_sasl_security_options = 

And in /etc/postfix/saslpd:

 smarthost   pellegrini:PASSWORD

(Is that correct? Should I really put the name of the smarthost there?)

But then, postfix complains that it can't find /etc/postfix/saslpd.db
(why did it add the "db" sufix to the file name?)

If I mv /etc/postfix/saslpd /etc/postfix/saslpd.db, postfix finds the
file, but says:

 fatal: open database /etc/postfix/saslpd.db: Invalid argument

I have postfix and  postfix-tls installed; it all works well if I don't
use the smarthost (but then there will be sites that will reject mail
from me, of course, because I have a dynamic IP...)

What is it that I'm doing wrong?

Thanks a lot!
J.

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