Well, dom_solariumdeparis, the way I see it you can either:
a) hack the spamassassin configuration file so that it points to your domain name WITHOUT the .com, or
b) you could rename the folder to add the .com (which may be more hassle than its worth), or
c) you could just create a symbolic link in /var/qmail/mailnames/mailnames/ that says both sdpinternational.com and sdpinternational point to the same folder.
Assuming you go with c above, the command-line way to do it would be:
cd /var/qmail/mailnames/mailnames/
ln -s sdpinternational sdpinternational.com
FYI: the general form of the ln command is:
ln [-s] file-name-that-exists-already file-name-to-create
the -s option means create a SYMBOLIC link -- the ONLY way to link to a directory
I hope this helps!
Dan
IT4SOHO