Don't want to post abroad - shall I suggest mail forwarding service?

[caker]

I don't want to post items abroad because if anything went wrong/seller wanted to return it would be a high postage I'd lose.
Someone has sent a message asking for a postage quote to Indonesia, but rather than just saying I won't post abroad I wondered about suggesting they use a mail forwarding service? Are they reliable, is it okay to send there (okay with Paypal?)
Thanks.

does it give online proof of delivery - if not, no.

Ah good point, I guess I wouldn't know that, although presumably if I sent it tracked the courier/Royal Mail would still confirm it? I'm not sure but I think it is like having a PO box, just with "a "real" address.