Can nor connect to optimum full site web mail

[mygsdsni]

I can not connect to optimum full site web mail over 3G. Optimum says I am signed in, I can get my voicemail and io. When I click on mail tab it just keeps asking me to sign in. If I am connected to WiFi, then I can get the full site web mail. Or... I can get the mobile optimum email.

I want to get Optimum full site web mail over 3G, any help appreciated.

Thanks!