Mail account settings for Lotus Traveler on the iPhone are LOCKED,
because they are automatically set when installing Lotus Traveler profile.
To change the settings connect to the Domino server running Lotus Traveler
and change the file:
Further information about the settings can be found in
<!-- Actual values are <true/> or <false/> if not using the ILNT_HostProtocol wildcard. -->
So changing the setting ILNT_HostProtocol to <false/> in Apple.xml shoudl do the trick.
Note: I didn't have to change this setting on our server and we also don't have SSL enabled... so could it be another issue?