I’m kind of jealous when I see all those cards from Africa. I have not yet received any single card from Africa, the Middle East and only 2 from South America, both from Brazil.
My lowest number is IN-23477 from 2011. But I must admit that I was not active from 2012-2019. 
I’m still about to receive a postcard with a reasonably low ID. Here’s mine, one of my only two 5-digits:
Some absolutely fabulous cards!!! 
I am looking forward to my next rare country postcard… whenever that will come! 
Thats my lowest postcard ID MT-19183 
i Was really happy
This is my lowest - from Uruguay
Today in the mailbox, but another beautiful postcard. Because it was a “second try”.
That the 2nd attempt sent on June 30, 2021
This is my lowest, of a country I even didn’t know existed 
I don’t have in my collection the postcards with 2 or 3 digits (so pity!), so the lowest postcard ID I have is
I have only one three digits ID, from Honduras!
My only three digits is from Fiji
Card #99 from Martinique
Mine is from Aland Islands. AX-9676
I was surprised
Lowest Postcard ID I received is from Aruba
I have recently received a postcard that is my new Lowest Postcard ID! It’s from Fujairah in the United Arab Emirates.
Mine is from the Fijis
I’ve only received 237 cards and I have 3 digits cards from: Montenegro, Tuvalu and Rwanda and a low 4 digit from Venezuela. My lowest ID I’ve sent was PR-1252.
The one I sent was:
I’ve also direct swapped back and forth to Cuba and Venezuela among other rare countries. I think living in a rare country has it’s advantages in postcrossing 
.
I’ve received a couple of 2-digit IDs:
And several more with 3 digits:
My lowest received card is XJ-62. My lowest sent card is HK-3. 