Open-xchange and possible proxy issue

[rt050]

Hi there,

I have somebody wishing to access their webmail via 123-reg using Open-Xchange.

They're unable to access it via the network but from home, other networks it's fine. I've opened all the common ports and the network has been up for almost a year now but never been able to access their webmail.

I'm running PfSense with a load balance and my DNS are from BT and Google. I was wondering if this is a possible proxy issue via the load balance?

Could anybody shed any light on my issue? I'm a bit stumped as I wouldn't have thought webmail would encounter any problems as all common ports, especially HTTP/HTTPS (and the other common ports).

Apologies if this is in the wrong section of the forum. :)