[EXT] Re: Whitelisting File Extension Types?

[Kelly Marchewa]

Thanks so much for the thorough explanation; I did not realize the 
software checked Mime parts. Great info; problem solved.

Thanks,
Kelly Marchewa
Software Engineer | Midamerica Hotels Corporation

On 3/24/22 17:26, Damian wrote:
>> I am not sure why it is finding an "asc" file as only a PDF was 
>> attached.
>
> The banned files mechanism checks mime parts, not only attachments.
>
>> Furthermore, even if I added ".asc" to the list above, it is still 
>> flagging the email as having banned content.
> A text-file attachment internally transforms to a list of strings:
>
>> ["multipart/mixed","application/octet-stream",".asc","file.txt"]
>
> Your default policy has to handle those mime-types appropriately.
>
> Example of a PDF inside a zip archive:
>
>> ["multipart/mixed","application/octet-stream",".zip","file.zip",".pdf","file.pdf"] 
>>
>
> A plain text body of a mail without attachments:
>
>> ["text/plain",".asc"]
> Your case probably has been:
>
>> ["multipart/mixed","text/plain",".asc"]
> ----------------------------------
> **THIS EMAIL ORIGINATED FROM OUTSIDE OUR ORGANIZATION. PLEASE BE VERY
> CAREFUL ABOUT OPENING ANY ATTACHMENTS, DO NOT ENABLE ANY CONTENT OR 
> MACROS
> IF PROMPTED, AND VERIFY THE EMAIL ADDRESS MATCHES THE SENDER. CONTACT 
> THE IT
> DEPARTMENT FOR ANY QUESTIONS.**
> ----------------------------------
>