customise mails that are sent ?

Hi all,
i was unable to find how to add the actual MS SQL SERVER name in my mail subject :

declare @Body varchar(4000)
select @Body = 'This mail was sent by server : ' + @@SERVERNAME

Doesn't seem to be correct syntax ?
+ how could i send the content of a specific log file (text file) in the mail body ?

thanks Florent