Prepare defaults and vars

Especially to be conform to RFC 2142 there are some predefinitions
needed
Also we need to make sure that those always are applied except they are
explicitly overwritten

https://tools.ietf.org/html/rfc2142

defaults/main.yml

@@ -2,3 +2,12 @@
 # defaults file for dotqmail
 dotqmail_prefix : ".qmail-"
 
+# Set root dotqmail file to maildir by default
+dotqmail_rootfile: ["./Maildir/"]
+
+# Those must be always present according to rfc2142
+# @see https://tools.ietf.org/html/rfc2142
+dotqmail_default_files:
+  "abuse": ["{{ansible_env.USER}}"]
+  "hostmaster": ["{{ansible_env.USER}}"]
+  "postmaster": ["{{ansible_env.USER}}"]