anchor.diff:            description = ''
               Bash statements run after a message has been inserted
               into the database and initial tags have been applied.
  +          '';
  +        };
  +      };
  +
  +      maildir = {
  +        synchronizeFlags = mkOption {
  +          type = types.bool;
  +          default = true;
  +          description = ''
  +            Whether to synchronize Maildir flags.
             '';
           };
         };
  
positive.code: 
        extraConfig = mkOption {
          type = types.attrsOf (types.attrsOf types.str);
          default = {
            maildir = { synchronize_flags = "true"; };
          };
          description = ''
            Options that should be appended to the notmuch configuration file.
          '';
  
negative.code:       {
          database = {
            path = config.accounts.email.maildirBasePath;
          };
  
          maildir = {
            synchronize_flags = cfg.maildir.synchronizeFlags;
          };
  
          new = {
  