olemus
väike lõhkeseade postisaadetise kujul, plahvatab avamisel

Wiktionary:
1. an explosive device sent through the post, triggered to explode when the letter or packet is opened

piltlikult
https://www.youtube.com/watch?v=h3AaCtWsv80

ülevaateid
https://en.wikipedia.org/wiki/Letter_bomb

https://en.wikipedia.org/wiki/Category:Deaths_by_letter_bomb

tõrje
https://www.letterbomb.eu/

https://www.sheriffdeputiesltd.com/warning-signs-of-letter-and-parcel-bomb/

https://www.strath.ac.uk/professionalservices/media/ps/estatesmanagement/security/Mail_Handling_Advice_Note.pdf