Hello all I recently added .gif to list of banned filetypes in the MIME acl as our answer to image spam. The reject message suggests that they zip it if they really want to send it. We're seeing rejections which suggest that this block is catching mailers using single pixel gifs as part of their html formatting arsenal.
The examples seen so far have been tiny, so I thought perhaps we could work around this by adding a second condition that checks that $mime_content_size is greater than 1k like this # File extension filtering. deny message = Blacklisted file attached ($mime_filename). Please zip if needed. condition = ${if match \ {${lc:$mime_filename}} \ {\N(\.gif)$\N}{1}{0}} decode = default condition = ${if >{$mime_content_size}{1k}{1}{0}} accept I've obviously fundamentally misunderstood something because this lets everything through! Could someone please point me in the right direction? Thanks Mark Douglas -- ______________ Postmaster and System Administrator Network Section IT Department School of Oriental and African Studies University of London Thornhaugh Street London WC1H 0XG -- ## List details at http://www.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://www.exim.org/eximwiki/