ROT42 tool to send ZIP files as email attachments

If you wish to report a GEMPACK bug or problem, we ask you to send us all files needed to reproduce the problems. A simple way to send 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 past times such restrictions 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. Renaming the ZIP to, say a ZAP suffix (as previously recommended here) 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 ZIP-ZAP method of sending files to GEMPACK support can no longer be used.

ROT42 method of sending a ZIP attachment

WARNING: The ROT42 method described below no longer works reliably on all email systems. It might SOMETIMES work !

We provide programs, ROT42 and WROT42, that can be used to temporarily translate ZIP files into another format(R42) that (some) email programs cannot look inside. To use them:

Place the files you wish to send into a zip archive.
Use the ROT42 or WROT42 program to translate the ZIP into a file with R42 suffix.
Send the R42 file as an email attachment, perhaps with a link to these instructions.
The recipient uses ROT42 or WROT42 to translate the R42 back into a ZIP.

Therefore both sender and recipient need to have the ROT42 or WROT42 program. WROT42 is a GUI (Windows) program, while ROT42 works from the command line. Both can be downloaded here.