Here are a few tips on receiving your posted goods safely:
Is your item being sent either Recorded Delivery or Special Delivery?
If the answer is 'yes' - have the seller email you the reference number when they post it.
(I place this number in the feedback as it avoids email issues & is plain for all to see.)
Why? Well - if you are either not in or just don't answer the door when Postie delivers - they'll leave you a P739 red card. That is, if they have bothered to bring any, or their pen is working! So if you have the reference number you can still approach the local Delivery Office aka Sorting Office to either collect, re-arrange delivery, or have it sent to a local Post Office for you to collect (Local Collect Service). Delivery Offices often have fairly draconian opening hours, and my local Brighton Office has dreadful parking, being a town centre location.
Just normal post then?
Measure your letterbox! If postie cannot get it thru the hole he'll do one of three things:
Fold it in half :)
'Doorstep' it. ie leave it outside your front door - hopefully somewhere inconspicuous - except to a resident!
Take it back to the office & hopefully leave a P739. But you never know.....
If you have a 'dogbox' on the back of your letterbox ensure that the packet length will not exceed the depth of the box. After all, no-one likes the sight of items of mail sticking out of their letterbox.
The best solution I've seen for small jiffy bag items is a wall-mounted mailbox.