InfoPath Dev

I'm relatively inexperienced with SharePoint (MOSS 2007), InfoPath and Active Directory, so excuse me if this is a silly question. We're building a forms portal in MOSS 2007, using InfoPath Forms Services with browser based forms. I'm looking into the possibilities for retrieving the current form user's email address within an InfoPath form hosted in Form Services. We're working with a complex AD structure with multiple root forests, with two way trusts set up between each root forest/domain. Based on what I've seen/read so far, the recommended option is to use a web service to retrieve the email address. Based on that I'm trying to determine the best approach for us to use. Would the Qdabra AD web service be a suitable option for this? I've seen that the Qdabra web service does not support multiple domains, but is this irrespective of any domain trust that may be set up? I've also looked at using the User Profile Database available out-of-the-box with MOSS and using the web service to retrieve the email address. However it seems like I'll need to configure the MOSS user profile DB to import from and sync with every domain individually, which I'd like to avoid as we currently have too many domains for this to be a suitable option. The current AD set up with multiple root forests is an issue we need to address separately, but this is likely to take a while to get right and we need this forms solution in place in the near future. Any tips or advice would be very much appreciated. Thanks

This is about as complex a structure as AD can get.  I can't guarantee it will work for this specific case, but it will require at least using the Global Catalog.  The syntax for the LDAP connection string would be GC://domain or GC://servername.

Give this a try and see if it works for this situation.

I have read a bit about the Global Catalog over the last couple of weeks, but I didn't think this also included users in trusted domains. I was under the impression the Global Catalog could be used to search for users within a single forest (which may contain multiple domains) and that each forest would have it's own Global Catalog. Does that sound right? I think that would mean I'd need to search each forest individually which would be a pain, given the number of forests currently in use. If I can use the Global Catalog to search all trusted domains as well then that would be great. Unfortunately I'm not in a position to test this at the moment as I don't have an environment set up where I could attempt this. The complex AD set up is only available in the production environment. We're looking to create a representative AD set up in our development environment, but this is not yet available either. Thanks for the advice, I'll try this when I have an environment to play with and I'll let you know how it goes.