I am currently using spamassassin successfully for my primary domain. But
spam appears to not be caught when it comes into the same server through
sendmail as a different domain. For instance, when mail is sent to
user@domain1.com spamassassin works good but when mail comes in as
user@domain2.com spamassassin seems to ignore. The email uses foreign
languages like Russian so seems like it should be caught.

It appears to not be a spamassassin setup but I assume it has to be done in
sendmail? I also want to note that I did configure sendmail to use procmail
but I am unsure of what procmail actually does. I at least have a ,procmail
file that is used.

I would really appreciate any help someone could give me.