Recently, I tried sending an attachment through gmail which failed. I also tried sending an attachment from a non-gmail account to a gmail user...it also failed. Some of the attachments I sent went through, while some others didn't. I contacted google about it, thinking it was some sort of bug. This was their reply:
Thank you for your message.
As a security measure to prevent the spread of potential viruses, Gmail
users cannot send or receive executable files.
Gmail does not accept executable files, even if they are sent in a zipped
format. If someone tries to send this type of message to your Gmail
account, the message will be bounced back to the sender.
We hope you enjoy Google's approach to email.
The Gmail Team
There is a way to easily get around this:
If you are sending executables, send a .rar file. It seems their scanners are just like AOL's and can't see into a .rar file to read it's contents.
Keeping this in mind, it would also be best for your privacy to send all attachment as .rar, no matter what email service you are using. Why let your ISP or anyone other than the intended reciever know what is being sent? That kind of snooping is equal to spyware, if you ask me, and all the major email providers are doing it. They call it "scanning for viruses" or "protecting you". I call it an invasion of privacy and a denial of service.