From eScan Wiki
MailScan for Exchange 2000/2003/2007 Setup (58.7MB)
http://update6.mwti.net/download/mailscan/ms550a/ms2x550a.exe
MailScan for SMTP Server Setup (57.8MB)
http://update6.mwti.net/download/mailscan/ms550a/mssm550a.exe
MailScan 5.5a for Mail-Server Setup (56.7MB)
http://update6.mwti.net/download/mailscan/ms550a/msms550a.exe
MailScan 5.5a for Lotus Notes Setup (56.9MB)
http://update6.mwti.net/download/mailscan/ms550a/msln550a.exe