diff --git a/api.spec.lua b/api.spec.lua
index f286cc8..64ad175 100644
--- a/api.spec.lua
+++ b/api.spec.lua
@@ -8,11 +8,23 @@ mail.register_recipient_handler(function(_, name)
     end
 end)
 
+local received_count = {}
+mail.register_on_player_receive(function(player)
+	received_count[player] = (received_count[player] or 0) + 1
+end)
+
+local sent_count = 0
+mail.register_on_receive(function()
+	sent_count = sent_count+1
+end)
+
 local function assert_inbox_count(player_name, count)
     local entry = mail.get_storage_entry(player_name)
     assert(entry, player_name .. " has no mail entry")
     local actual_count = #entry.inbox
     assert(actual_count == count, ("incorrect mail count: %d expected, got %d"):format(count, actual_count))
+    local player_received = received_count[player_name]
+    assert(player_received == count, ("incorrect receive count: %d expected, got %d"):format(count, player_received))
 end
 
 mtt.register("send mail", function(callback)
@@ -22,6 +34,7 @@ mtt.register("send mail", function(callback)
     assert(not err)
     assert_inbox_count("player2", 1)
     assert_inbox_count("player1", 0)
+    assert(sent_count == 1)
 
     -- send a second mail to the list and also the sender
     success, err = mail.send({from = "player1", to = "list/test, alias/player1", subject = "something", body = "blah"})
@@ -29,6 +42,7 @@ mtt.register("send mail", function(callback)
     assert(not err)
     assert_inbox_count("player2", 2)
     assert_inbox_count("player1", 1)
+    assert(sent_count == 2)
 
     -- send a mail to list/reject - the mail should be rejected
     success, err = mail.send({from = "player1", to = "list/reject", subject = "something", body = "NO"})
@@ -36,6 +50,7 @@ mtt.register("send mail", function(callback)
     assert(type(err) == "string")
     assert_inbox_count("player2", 2)
     assert_inbox_count("player1", 1)
+    assert(sent_count == 2)
 
     callback()
 end)