diff --git a/README.md b/README.md
index 02561fd..628a315 100644
--- a/README.md
+++ b/README.md
@@ -36,11 +36,6 @@ Overview:
 * `v2` every player has its own (in-) mailbox in the `<worldfolder>/mails/<playername>.json` file
 * `v3` every player has an entry in the `<playername>` modstorage (inbox, outbox, contacts)
 
-Mails in the v1 format are supported until commit `b0a5bc7e47ec1c75339e65ec07d0a0ac2b17288b`.
-Everything after that assumes either the v2 or v3 is used.
-
-For a v1 to v3 migration the version in `b0a5bc7e47ec1c75339e65ec07d0a0ac2b17288b` has to be at leas run once (startup).
-
 # Dependencies
 * None
 
diff --git a/migrate.lua b/migrate.lua
index a76f801..0623b97 100644
--- a/migrate.lua
+++ b/migrate.lua
@@ -1,6 +1,38 @@
 
 local STORAGE_VERSION_KEY = "@@version"
 
+local function migrate_v1_to_v3()
+	local file = io.open(minetest.get_worldpath().."/mail.db", "r")
+	assert(file)
+	print("[mail] Migration from v1 to v3 database")
+
+	local data = file:read("*a")
+	local oldmails = minetest.deserialize(data)
+	file:close()
+
+	for name, oldmessages in pairs(oldmails) do
+		local entry = mail.get_storage_entry(name)
+		for _, msg in ipairs(oldmessages) do
+			if msg.to then
+				table.insert(entry.inbox, {
+					id = mail.new_uuid(),
+					from  = msg.sender or msg.from,
+					to      = msg.to,
+					subject = msg.subject,
+					body    = msg.body,
+					time    = msg.time,
+				})
+			end
+		end
+		mail.set_storage_entry(name, entry)
+	end
+
+	-- rename file
+	print("[mail] migration done, renaming old mail.db")
+	os.rename(minetest.get_worldpath().."/mail.db", minetest.get_worldpath().."/mail.db.old")
+	mail.storage:set_int(STORAGE_VERSION_KEY, 3)
+end
+
 local function read_json_file(path)
 	local file = io.open(path, "r")
 	local content = {}
@@ -12,21 +44,13 @@ local function read_json_file(path)
 	return content
 end
 
-
-function mail.migrate()
-	local version = mail.storage:get_int(STORAGE_VERSION_KEY)
-	if version < 3 then
-		mail.migrate_v2_to_v3()
-		mail.storage:set_int(STORAGE_VERSION_KEY, 3)
-	end
-end
-
 -- migrate from v2 to v3 database
-function mail.migrate_v2_to_v3()
+local function migrate_v2_to_v3()
 	minetest.mkdir(mail.maildir) -- if necessary (eg. first login)
 	print("[mail] Migration from v2 to v3 database")
 
-	minetest.after(0,function()
+	-- defer execution until auth-handler ready (first server-step)
+	minetest.after(0, function()
 		for playername, _ in minetest.get_auth_handler().iterate() do
 			local entry = mail.get_storage_entry(playername)
 
@@ -53,5 +77,21 @@ function mail.migrate_v2_to_v3()
 
 			mail.set_storage_entry(playername, entry)
 		end
+		print("[mail] migration done")
+		mail.storage:set_int(STORAGE_VERSION_KEY, 3)
 	end)
 end
+
+function mail.migrate()
+	local v1_file = io.open(minetest.get_worldpath().."/mail.db", "r")
+	if v1_file then
+		-- v1 to v3
+		migrate_v1_to_v3()
+	end
+
+	local version = mail.storage:get_int(STORAGE_VERSION_KEY)
+	if version < 3 then
+		-- v2 to v3
+		migrate_v2_to_v3()
+	end
+end
\ No newline at end of file