EICAR test virus, RAR
Test your virus checker with this email. It has a RAR archive attached to it that contains the EICAR test virus (see EICAR test).
Any antivirus program should be able to detect the EICAR test file, even within the RAR archive - at the very latest, when the archive is opened. If your emails are filtered at the email gateway, the virus scanner should detect the file attachment as a virus and not let the email through, at least not with the file attached.
Warning: If your provider or another mail gateway filters your emails for viruses, this email may never reach you.