Thankfully (to date), I have had nothing go missing between here and the UK. Although it does take longer to arrive via Correos
(10 days there compared with 3 - 5 getting here from my family members).
I have had gifts/cards go missing from UK and USA to here… Even though I take the precaution of having a PO Box (otherwise I wouldn’t get my mail anyway being in the campo!)...
From time to time I use the Offex postal system for sending letters to UK. Just a little bit more expensive than Sp postal system, but have never had anything go missing, and it is a whole lot quicker!
Although we have mail boxes at a communual point in our area, mail never arrives as the postie just chucks it in the bushes (yes, we have seen them dispose of it rather than deliver it to its delivery point!)
Fuengirola is no 2 for unsorted lost items, Estepona no 1!!
Thankfully our mail comes straight to our sub district post office in the Pueblo and by passes Fuengirola.
Mixed experiences, but generally OK since I stick to using local PO in village.