I have a number of remote users who complain that when visiting some organisations their Groupwise in remote mode doesn't work, yet from their homes, and most other remote locations (airports, hotels) the email synchs fine. They do have the web access to fall back on but most prefer the full synch for offline access.

I believe the issue stems from outbound port filtering on the fire wall of the organisations they are visiting, where outbound port 1677 is blocked.

I have seen RPC/HTTPS in action on Outlook in Exchange environments and it seems to work OK from any location.

The options I see to get around this for Groupwise are:
- use an SSL VPN
- change our firewall inbound forwarded port from 1677 to 80 or 443 which may then work at other organisations, though Deep Packet Inspection firewalls may not allow this in any case.

What are other's experiences in this sort of situation?? Am I on the right track with fixing the problem??