> Yes, and thankfully these days it's fairly easy. If performance is an > issue you might want to lean towards libspf2 rather than Mail::SPF > (the reference implementation). A full list of milters and other > resources for setting up SPF (howtos etc) is here: [...] Thank you! I tried before on SL 4.5, but got lost trying to resolve failed dependencies when installing the necessary packages. I'll give it another try - now with SL 5.1. Miguel A. Lerma