"Enable POP from now on" feature

Is it possible to configure options on email server containing defalut Virtulamin stack (Postfix, Dovecot) features similar to Gmail settings:

1. Enable POP for all mail (even mail that's already been downloaded)

2. Enable POP for mail that arrives from now on

It would be great if users connected to their usermin interface could choose these options. Maybe it can be done in Postfix/Dovecot config or in other hardcoded way?

For example user configured email account on computer A. He downloaded 10 messages. Then he went to computer B and configured the same email account. Computer B does not redownload 10 messages while user not checked "Enable POP for all mail (even mail that's already been downloaded)"

Gmail has this feature. Zimbra also has this feature, and as far as I know Zimbra is based on Postfix.

Thanks