Document mail module.

doc/utils.md

@@ -183,6 +183,22 @@ most scheme implementations.
 Returns a list containing only elements matching given ```pred?```
 predicate.
 
+### Mail
+
+    (import util-mail)
+
+A simple wrapper module to send emails from UNIX system.
+
+    (send-mail body-lines [#:from from] [#:to to] [#:subject subject])
+
+* ```body-lines``` - lines of the email
+* ```from``` - email address from string
+* ```to``` - email address to string
+* ```subject``` - email subject string
+
+Sends email using mail(1) command. The arguments ```#:to``` and
+```#:subject``` are mandatory. Argument ```#:from``` is optional.
+
 ### Parser
 
     (import util-parser)