How do you send mail?

Then, after doind what you have done, which is the first steps, you trade the Pokemon, and your friend takes the mail off and reads it. Hope I helped, and this is he right answer, so even if it makes you unhappy, please rate this high.

You can't send a message but you can make a Pokemon hold it and give it to a friend and your friend will read the mail and like this it is sent to him via the Pokemon that was holding it.

Here's something else I've found, which surprised me:

Attach your mail after writing what you wish on it, and put that Pokemon (mail still attached to the pokemon) into the day care center. If you have a friend that can do that also, request that they do so. Then trade records. (Now, I consider myself a poketard, since I went and bought another gba for trading, and this neat trick); Go and mix records. Now here's the cool part: if the Pokemon like each other, they may just exchange the mail. I've tried this before, and it works, but I need to try it again since it's been awhile. If it works for you, good. If not, please don't get mad at me since it's been a very long time.