Which is total crap and shows how you shouldn't trust armchair lawyers. Ignoring whether that act applies to express courier services:
Interfering with the mail: postal operators.
(1)A person who is engaged in the business of a postal operator commits an offence if, contrary to his duty and without reasonable excuse, he—
(a)intentionally delays or opens a postal packet in the course of its transmission by post, or
(b)intentionally opens a mail-bag.
Now, taxation is a valid reason to delay, as is opening to check for prohibited or restricted items.
Then we have:
(3)Subsection (1) does not apply to the delaying or opening of a postal packet in accordance with any terms and conditions applicable to its transmission by post.
All couriers have taxes and duties as part of their T&Cs.
i was very dubious to be honest but thought id mention it
