Samsung SmartThings Multipurpose Sensor https://www.amazon.com/dp/B0118RQW3W/ref=cm_sw_r_cp_apa_WWvlAbACP9MDJ

Samsung SmartThings Motion Sensor https://www.amazon.com/dp/B01IE35PCC/ref=cm_sw_r_cp_apa_CXvlAb676DKXD

I got this one - Open close sensor....

https://smile.amazon.com/gp/product/B0118RQW3W/ref=pe_385040_215884960_pd_te_s_gc_ti/164-2669327-9202902?_encoding=UTF8&pd_rd_i=B0118RQW3W&pd_rd_r=WQRSKQZVYPN1WE0D03KZ&pd_rd_w=cnDQV&pd_rd_wg=XUvKj

edit and this is the mailbox

https://smile.amazon.com/gp/product/B008HVH502/ref=oh_aui_search_detailpage?ie=UTF8&psc=1

Don't feel too bad. People will talk up Samsung's reasonable sensor prices, but the reliability of these devices has been spotty at best for me and many others.

Edit: Do you guys not remember how horribly unreliable a lot of their sensor hardware was? https://www.amazon.com/gp/aw/d/B01IE35PCC/ref=cm_cr_arp_mb_bdcrb_top?ie=UTF8 https://www.amazon.com/dp/B0118RQW3W/ref=cm_sw_r_cp_apa_fabc_EpIRFb33YMF14