All clients that host their domains email accounts with us have web based access to their email (WebMail) as well as the normal POP or IMAP approach.
If you are hosted on our New Zealand network or one of our newer UK servers then life's easy. Simply goto http://www.yourdomain.co.nz/webmail/ (replacing www.yourdomain.co.nz with whatever you own web sites web address is).
Or use you favourite email application on any PC or device to access your emails via POP or IMAP as described here https://my.slightlydifferent.co.nz/knowledgebase/8/General-Email-Server-Settings.html