Do out-of-office responses reflect in the analytics?

Out-of-office responses do not show in the analytics as they are not considered actual replies, which is why they do not trigger the reply event.

How to automatically resume a campaign when the prospect is back in office?

First, you need to disable "Stop on auto-reply" in the campaign's advanced options.
Second, you need to enable the "Automatically tag interest status in replies" option, in your Account settings/Preferences. More info here.

How to stop them from appearing in the Unibox?

If you do not want to get auto-replies in Unibox, kindly disable "Show auto-replies in Unibox" in settings.

What happens to Out of office leads when I don't have "Stop on auto-reply" enabled?

If the “Stop on auto-reply” has not been enabled, please enable the "Automatically tag interest status in replies" option in the Settings/Preferences tab, under AI Automation section.

By doing so, the AI will be able to detect out-of-office replies and pause communication until the specified return date automatically, ensuring your emails reach leads when they are back in office. Check more details here.