How does one go about redirecting mail without :-

1. Having to pay Royal Mail £111 + to send all your mail & spam to NZ.

2. Putting a willing relative out to filter & post the darn stuff at great expense.

What if like me your going to leave the UK not knowing your forward mailing address, can post boxes be arranged in advance in NZ when you know at least which town your heading to?

What's the best option folks?