Which free email service will allow me to attach an executable file?

Hey guys. I recently purchased "Spytector", found this forum while googling info about it and found it quite helpful. I'm hoping you guys have some more answers for me as I have a lot to learn.

Most importantly, I tried emailing the server through Yahoo multiple times only to later find out that Yahoo doesn't even allow the sending of an .exe file, nor do most free email services for that matter.

What free email service can I use that will allow me to send it? And if the person receiving the server has Yahoo, will they not be able to access the file anyway, despite what service I use to send it? The person I'm trying to send it to also has an email account through their school. Would that be a better place to send it? Or are those accounts typically just as strict?

As for the rest of this process, I believe I've figured most everything else out. Spytector seems pretty user friendly and self explanatory, but there's a couple of other things I'm a bit shaky on.

I'm still a little unsure about what port to choose for the email option after googling some info about that. Apparently port 25 is often blocked, but I'm not sure what would be the proper alternative. I'm using a Mac which I thought may be different from most computers as far as internet settings go. Does it not matter? Does it depend on the receiving computer's settings more so than mine?

Lastly, I found out that Spytector's email service isn't compatible with Yahoo mail either. I set it up with a Gmail account? Will that work?

I've sent the file once already and it wouldn't be practical to send it many more times. I'd like to get it right once and for all so I can carry this out properly. I appreciate any help you can offer. Thanks...