I'm trying to send an email with a file attachment from a Solaris 9 box using the follwoing:

(/usr/bin/cat file_containig_body_of_email.txt; /usr/bin/uuencode file1.txt file1.txt) | /usr/bin/mailx -c  "address1@domain.com" -s "This is a test" "address2@domain.com" "address2@domain.com"
Where file_containig_body_of_email.txt contains the body of the email, example This is the body of the email

The above works for emails where the body of the email is in plain text, however I would like to send the body of the email (with file attachment) formatted using HTML., as you can see the above command simply dumps whatever is in file_containig_body_of_email.txt file in the message body of the email, obviously, I can't simply put the HTML formatted message in the

Is there an alternative way of doing this using only mailx and/or sendmail ?