Why user-hostile policies are a bad thing and a mistake
One reasonable reaction to limited email retention policies being user-hostile is to say basically 'so what'. It's not really nice that policies make work for users, but sometimes that's just life; people will cope. I feel that this view is a mistake.
The problem with user-hostile policies is that users will circumvent them. Generously, let's assume that you enacted this policy to achieve some goal (not just to say that you have a policy and perhaps point to a technical implementation as proof of it). What you really want is not for the policy to be adhered to but to achieve your goal; the policy is just a tool in getting to the goal. If you enact a policy and then your users do things that defeat the goals of the policy, you have not actually achieved your overall goal. Instead you've made work, created resentment, and may have deluded yourself into thinking that your goal has actually been achieved because after all the policy has been applied.
(Clearly you won't have inconvenient old emails turn up because you're deleting all email after sixty days, right?)
In extreme cases, a user-hostile policy can actually move you further away from your goal. If your goal is 'minimal email retention', a policy that winds up causing users to automatically archive all emails locally because that's the most convenient way to handle things is actually moving you backwards. You were probably better off letting people keep as much email on the server as they wanted, because at least they were likely to delete some of it.
By the way, I happen to think that threatening punishment to people who take actions that go against the spirit or even the letter of your policy is generally not an effective thing from a business perspective in most environments, but that's another entry.
(As for policies for the sake of having policies, well, I would be really dubious of the idea that saying 'we have an email deletion policy so there's only X days of email on the mail server' will do you much good against either attackers or legal requests. To put it one way, do you think the police would accept that answer if they thought you had incriminating email and might have saved it somewhere?)