MIME Types

Deeztek Support support at deeztek.com
Thu Oct 2 14:04:04 CEST 2014


> You can easily add any mime-type to the $banned_filename_re or
> $banned_namepath_re lists.
>
> But keep in mind the mime-type is declared by the sending mail
> client and can be set wrong, either by buggy software or an
> attacker.  Amavis does not "normalize" the mime-type.
>
> As a general rule, using the file extension as determined by file(1)
> and @map_full_type_to_short_type_re is more reliable for blocking
> specific file types since it doesn't depend on information provided
> by the client.
>
>
>
>    -- Noel Jones
>

I guess I was mistaken that using the mime-type was more reliable than 
using a file extension since the file extension can be easily modified 
also? So, if I were to ban .rar files, and someone send me a rar file 
called "archive.rar" but they renamed it to "archive" it will still be 
blocked by Amavis?


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