We currently use Vipre for Exchange for email scanning and filtering, and that system has no way to define a whitelist of external senders who are exempt from attachment filtering.
I am considering a trial of the Barracuda 300 device for anti-virus and spam ( we already use the message archiver ) and need to verify that we truly can specify a whitelist of external email addresses whose attachments do not get processed by attachment filtering. From what I have read here, it appears to me that if one of the whitelisted senders sends a message containing a virus in the attachment that it will still get stopped, but that their "clean" attachments will be allowed through even if the file is of a type that would otherwise be filtered. Is my understanding correct?