After deleting swiftmail (upgraded to newer version on old server), things are fine again.
But after reinstall using the extension manager its broken again.
2016/08/29 16:00:14 [error] 11465#11465: *33 FastCGI sent in stderr: "PHP message: PHP Parse error: syntax error, unexpected 'new' (T_NEW) in /www/dokuwiki/lib/plugins/swiftmail/action.php on line 44" while reading response header from upstream, client: 192.168.5.20, server: oscamwrt.mooo.com, request: "GET /doku.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "192.168.5.10"
2016/08/29 16:00:15 [error] 11465#11465: *33 FastCGI sent in stderr: "PHP message: PHP Parse error: syntax error, unexpected 'new' (T_NEW) in /www/dokuwiki/lib/plugins/swiftmail/action.php on line 44" while reading response header from upstream, client: 192.168.5.20, server: oscamwrt.mooo.com, request: "GET /doku.php HTTP/1.1", upstream: "fastcgi://127.0.0.1:9000", host: "192.168.5.10"