Qmail relaying with SMTP-AUTH

[snookersky]

Because of the SPF filters, some of my mails are filtered out at the destination if I am sending them through qmail of my Plesk-server. So I want to use another server - the one with the SPF record - as a relay host with SMTP-AUTH (with user/password). Can anyone tell me where can I configure this? I am thinking of some rules to use the relay server only if the sender has a specific mail address...

 

[Ragefast]

Wouldn't it be faster and easier to add your IP to the SPF record for your domain?

 

[snookersky]

Of course it would be easier to enter another SPF record, but I am no administrator on the other server - It's just an account I have on my previous ISP - and I don't want to give up my "wellknown" mailaddress :-(