Attachments banned by google

Routine attachment extensions banned by Google.  If the are going to be attached, they will need to be renamed and hidden.  Usual method is to create either a tgz or zip file containing the files, and then rename that attachment.  Usual that seems to work is to reverse the spelling of the file.

So far google doesn't seem to vet the attachment with the "file" type as well as the extension, because presumably software at the receiving or download end ignores it if the extension doesn't match.

http://www.computerworld.com/article/3161898/security/gmail-will-block-javascript-attachments-a-common-source-of-malware.html

Users will no longer be able to attach .JS files to emails in Gmail, regardless of whether they attach them directly or they include them in archives like .gz, .bz2, .zip or .tgz. For those rare cases when such files need to be shared via email, users can upload them to a storage service like Google Drive and then share the link.
The .JS file extension will be added an existing list of other banned file attachments that includes: .ADE, .ADP, .BAT, .CHM, .CMD, .COM, .CPL, .EXE, .HTA, .INS, .ISP, .JAR, .JSE, .LIB, .LNK, .MDE, .MSC, .MSP, .MST, .PIF, .SCR, .SCT, .SHB, .SYS, .VB, .VBE, .VBS, .VXD, .WSC, .WSF and .WSH. Most of these file types have long been abused by cybercriminals to send malware via email.