Using pathogen installation is easy:
% gem install mail netrc
% cd ~/.vim/bundle
% git clone http://github.com/ferranpm/vim-mail
Setting server properties
let g:mail_smtp_server="smtp.gmail.com"
let g:mail_smtp_port=587
let g:mail_imap_server="imap.gmail.com"
let g:mail_imap_port=993
let g:mail_imap_ssl=1
Setting user/password can be done in your .vimrc
let g:mail_address="myusername@gmail.com"
let g:mail_password="PassWord1234"
Or in a file specified by g:mail_netrc
let g:mail_netrc="~/.netrc"
Don't forget to put the information in that file!
machine smtp.gmail.com
login myusername@gmail.com
password PassWord1234
machine imap.gmail.com
login myusername@gmail.com
password PassWord1234
Use :WriteMail to create a new message. This command will prompt for the
recipients to send the message to (the list ends with an empty address).
The :Mail command puts you in the root folder of your mail.
On every screen, there's information on the status line about what can be done.