Hey Rich,
One of our products have a yearly support contract and I was investigating if LimeLM has the ability to send emails to customers when their key is within a certain range of expiring.
Well, the answer is yes, but LimeLM doesn't send emails (you'd have to do it in your own script).
The way you'd do it is to use the limelm.pkey.advancedSearch web API function to search for product keys with a field value in the range you provide.
For example, let's say you have a field value of Date /Time type called "expires_on". Let's say you want to get all product keys that have expired or will expires 2 weeks from now. The way you'd get these keys is to use the "feature_name[]", "feature_value[]", and "feature_match[]" parameters of the limelm.pkey.advancedSearch web API function.
Specifically for the "feature_name[]" you'd use "expires_on", for "feature_value[]" you'd use "2013-04-16" (i.e. the value that's 2 weeks from when the script is run), and for "feature_match[]" you'd use "before".
Then after getting the list of product keys you can shot an email to the users. Of course you can also limit the scope of the returned results by using a "feature_match[]" of "between" to just find keys that are about to expire but ignoring keys that have already expired.
Or you can do whatever is best for your use case (maybe only reminding expired users every N weeks).
Tell me if that helps.