implement qutoas

mail-server/dovecot.nix

@@ -32,6 +32,7 @@ in
       enableImap = enableImap;
       enablePop3 = enablePop3;
       enablePAM = false;
+      enableQuota = true;
       mailGroup = vmailGroupName;
       mailUser = vmailUserName;
       mailLocation = dovecot_maildir;
@@ -80,6 +81,11 @@ in
           args = ${passwdFile}
         }
 
+        userdb {
+          driver = passwd-file
+          args = ${passwdFile}
+        }
+
         service auth {
           unix_listener /var/lib/postfix/queue/private/auth {
             mode = 0660