ZIP files and ZAP files

If you wish to report a GEMPACK bug or problem, we ask you to send us all files needed to reproduce the problems. Usually the simplest way to send us several files is to bundle them up together in a ZIP archive.

However, some mail services (including GMail or Google Mail) do not allow you to send or receive attached files of the following types (extensions):

EXE, BAT, CHM, PIF, DLL, CMD, SCR, COM, LIB, VB, VBE, VBS, and some others.

Your organization may impose similar restrictions. In the past such restriction could sometimes be avoided simply by packing EXE or other forbidden files into a ZIP archive. However, this will not work for Gmail. Gmail will see the EXE inside the ZIP and reject it. However it seems that if you put EXE files in, say, MyFiles.ZIP, then rename that to MyFiles.ZAP, then attach the ZAP file to your email, the ZAP will pass through GMail without any problem.

Update: ZAP renaming may no longer work

Renaming the ZIP to, say a ZAP suffix may fool Gmail, but some other corporate email programs are able to detect that the ZAP file is actually just a renamed ZIP, and will detect EXE files inside it (and so reject it). That is the case with the mail servers at Victoria University (where GEMPACK is based). Therefore the ZAP method of sending files to GEMPACK support can no longer be used. Instead we suggest this ROT42 method of sending a ZIP attachment.

If you want to use the ZAP method in another context, proceed as follows:

To send files in a ZAP

Zip up the files in your usual way.
Change (rename) the ZIP extension to ZAP.
Attach the ZAP file to your email.

If you receive a ZAP file as attachment

Save it to your hard disk.
Change (rename) the ZAP extension to ZIP.
Unzip it in your normal way.