Question
I find that if I try and send an MS Word file in docx format through my server it is blocked as having a banned attachment. If I save the same file as an MS Word file in doc format it passes through the same checks OK. Why would this be?
Answer
MS Word files in docx format are in fact zip files. You can rename a .docx to .zip and open it as a regular zip file if you wish. The docx file is treated correctly as a zip file by GMS and all checks you have enabled for zip files get applied.
If you do rename with a zip extension and open the file you will most likely find that it either contains another file with an extension which you have banned from being accepted by your server, or that there are multiple levels of zip files.
To rectify this you will need to go to the Anti-spam > Message Content > Attachments page in the GMS administration interface and amend the settings appropriately. It is likely that the feature causing the problem is "Reject zip files within zip files".
Note: disabling this feature means you will not be protected from "zip bombs"
Keywords:Word docx attachment blocking