Write me vs. write to me

"I will write you a mail with ***"

or is it correct ONLY if we say

"I will write a mail TO YOU with ***"

From the dictionary.com, when using "to write" to express the idea of writing a letter or communicating by letters, the verb is intransitive.

This seems to me that only the second usage is correct, UNLESS there are very subtle differences in the usage/meaning of the verb in

those two scenarios.

"I'll send it to you in 3 e-mails because of its size."

I'm quite certain mail is uncountable. Email is debatable. I believe hardcore grammarians would use it as an uncountable noun. You might want to wait for native speakers.

I just thought it was possible to use 'e-mails' as countable. But I like your version.

<EDIT>GG, actually the meaning of email in your version is the name of the technology for sending electronic messages over the Internet like FTP, HTTP, Javascript. For example, ftp port, html file. It's not the message itself like mail does, I believe. I hope I'm not confusing the questioner.

New2Grammar gave you good advice: Just say "Write to me."