Have you ever noticed that email programs will block certain file types?
To reduce the spread of spam and viruses, email services block the ability to send certain files, namely executable files. Executable files are self contained programs which can be run by opening them. Every program on your computer is launched using an executable file. In the file sharing world, these executable file types, in nearly all forms, have been singled out as a security threat.
Most email services will completely block any executable file type that is attached to an email. If your job requires you to share an executable file, such as software programmers or developers, email attachment blocking will diminish your ability to easily share your projects with others.
So what files do the large free email providers NOT let you share? The list is surprisingly large.
Google’s Gmail will block files with the following extensions: .ade, .adp, .bat, .chm, .cmd, .com, .cpl, .exe, .hta, .ins, .isp, .jse, .lib, .mde, .msc, .msp, .mst, .pif, .scr, .sct, .shb, .sys, .vb, .vbe, .vbs, .vxd, .wsc, .wsf, and .wsh.
Yahoo! Mail is less aggressive, but still blocks the most common executable files, including: .exe, .com, .vbs, .lnk, .pif, .scr, .bat.
So you might be thinking that you can just compress these files into a single folder right? Well you will be disappointed to learn that Gmail also scans compressed files (.zip, .tar, .tgz, .taz, .z, .gz, and .rar) and blocks these files if an executable format is detected.
Microsoft Exchange, a popular business email platform, is quite aggressive, and by default will block the most file types, including: .ade, .adp, .app, .asp, .bas, .bat, .cer, .chm, .cmd, .cnt, .com, .cpl, .crt, .csh, .der, .exe, .fxp, .gadget, .hlp, .hpj, .hta, .inf, .ins, .isp, .its, .js, .jse, .ksh, .lnk, .mad, .maf, .mag, .mam, .maq, .mar, .mas, .mat, .mau, .mav, .maw, .mda, .mdb, .mde, .mdt, .mdw, .mdz, .msc, .msh, .msh1, .msh2, .mshxml .msh1xml, .msh2xml, .msi, .msp, .mst, .ops, .osd, .pcd, .pif, .plg, .prf, .prg, .pst, .reg, .scf, .scr, .sct, .shb, .shs, .ps1, .ps1xml, .ps2, .ps2xml, .psc1, .psc2, .tmp, .url, .vb, .vbe, .vbp, .vbs, .vsmacros, .vsw, .ws, .wsc, .wsf, .wsh, and .xnk.
Overall, the blocking of executable file types from email has had a positive security effect and raised the minimum level of security for the entire email ecosystem, but has done so at the expense of legitimate users. Since the email user cannot control the file types blocked by email services, the only option is to seek alternative file sharing services such as managed file transfer.
At SendThisFile, we know that blocking file types limits legitimate uses of file sharing, and we allow you to share large files of any type. So if a programmer needs to send large files that are executable, they can do so. The recipient will receive a download link that opens a SendThisFile download page from which the file can be downloaded.
Photo Source: Flickr ladybeames