I'm not sure about the stable release of IP but it looks like there is no real way to automatically re-send account validation e-mails out to inactive users with IP 1.1.10.25.  You can, however, direct the users needing validation to this link:

If you have IP installed in a folder on your server:



This is the way I have always handled these situations.

Hope that helps.

On my login screen theres a link which resends validation to users.

You could take that link from yours and place it somewhere more visible if you'd like.

There used to be a mod for this type of deal.  In the ACP, you could click a link that would show you all the inactive users and give you the option of mass-emailing them.  In the e-mail, it would let them know their account was subject to deletion if they remained inactive.  To be honest, the mod didn't do any good...to my knowledge.

Maybe you could find that mod and try it out on IP?