As from 24th May 2017, greylisting is disabled by default on all domains due to problems that it had been starting to cause for reliable email delivery from some third party senders.

If you would like to enable greylisting on one or more domains that you host with us, please contact support to make the request and we can arrange it for you. Please be aware that it may cause issues receiving emails from some senders, due to configuration issues at their end.