I've never come across this one before, so I'm hoping to call upon the knowledge of the collective to answer this.

I have a client, who when he receives a *.zip file via email, it arrives as an *.efw formatted file.

Has anyone see this before?

I finally found some information on this (was send it by a gentleman who read my post on a forum somewhere).

This happens with some CA products, where the anti virus software renames the file (why I haven't been able to determine).

You are able to rename the file with a .zip extension, and everything works fine. Just a pain for those who it affects.

Thank you for the information. My first experience with CA tonight 10/13/07 was with an efw file. I came about you with a google search with efm files and sent me to the planet with this forum and I wanted to reply to you so I registered. This is an awsome place the planet. God bless everythig that walks, crawles, slithers, swims and flies, I hope we all feel that. Thank you...

Sorry to bump this, I was just searching and came across this. You can also disable the renaming in the Personal Firewall, e-mail section. I wrote full instructions for disabling .efw files here.