I encrypted a folder with this command:tar -zcf - rails_project | openssl des3 -salt -k 123456 | dd of=rails.tar.gzAttached it to a mail, press send, and voila, error message that I can't attach executable files. How in the world can Gmail know what's inside!?
How does Gmail know there is an executable file within an encrypted file?
gmail
See this Gmail help page: Some file types are blockedI'm guessing the Gmail does not allow you to send or receive files that are corrupted part is what applies here (but the Gmail programmer neglected to give a more specific error message for this case). That is, Gmail is checking your .tar.gz file and finding that it's invalid.I'd suggest using a different extension so Gmail doesn't think it's a corrupt tarball. I just tested this hypothesis, and it seems to be correct. I used the .gpg extension, though I'm sure any number of extensions not on their blacklist would work just as well.