Password expiring in 2 days, but policy is not set

I discovered an interesting issue.

When we set a password for a new user, it is setting the max password age to 2 days, even though there is no policy set for password age.

We have 3 domains and this is only happening to the one, which is the forest.

I came across some searches pointing to fine-grained password, however we are not using fine grained password settings as we are using Windows Server 2003 as a Forest and domain level.

Any ideas?