empty sender

Hello! Today several users recieved an email with an empty sender and attached file 3282023.gz with 3282023.scr inside, I'm pretty sure it is a virus, because nobody really use or send screensavers anymore. :) I already set backscatter score to 3, but I guess it will also quarantine all...

Hi there, I have a problem and maybe someone on here can help me. I have read a lot of posts on this forum already, but I haven't fount a solution yet. Maybe I have not looked up the correct keywords. So any help is appreciated. Our PMG receives a lot of spammails from mailservers like these...