diff --git a/server/message_cache.go b/server/message_cache.go
index 8e787db3..c685d6a4 100644
--- a/server/message_cache.go
+++ b/server/message_cache.go
@@ -65,13 +65,13 @@ const (
 	selectMessagesSinceIDQuery = `
 		SELECT mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
 		FROM messages 
-		WHERE topic = ? AND id > ? AND published = 1 
+		WHERE topic = ? AND id >= ? AND published = 1 
 		ORDER BY time, id
 	`
 	selectMessagesSinceIDIncludeScheduledQuery = `
 		SELECT mid, time, updated, topic, message, title, priority, tags, click, attachment_name, attachment_type, attachment_size, attachment_expires, attachment_url, attachment_owner, encoding
 		FROM messages 
-		WHERE topic = ? AND (id > ? OR published = 0)
+		WHERE topic = ? AND (id >= ? OR published = 0)
 		ORDER BY time, id
 	`
 	selectMessagesDueQuery = `
@@ -95,7 +95,7 @@ const (
 
 // Schema management queries
 const (
-	currentSchemaVersion          = 5
+	currentSchemaVersion          = 6
 	createSchemaVersionTableQuery = `
 		CREATE TABLE IF NOT EXISTS schemaVersion (
 			id INT PRIMARY KEY,
@@ -173,6 +173,11 @@ const (
 		ALTER TABLE messages_new RENAME TO messages;
 		COMMIT;
 	`
+
+	// 5 -> 6
+	migrate5To6AlterMessagesTableQuery = `
+		ALTER TABLE messages ADD COLUMN updated INT NOT NULL DEFAULT (0);
+	`
 )
 
 type messageCache struct {
@@ -326,7 +331,15 @@ func (c *messageCache) messagesSinceID(topic string, since sinceMarker, schedule
 	if err != nil {
 		return nil, err
 	}
-	return readMessages(rows)
+	messages, err := readMessages(rows)
+	if err != nil {
+		return nil, err
+	} else if len(messages) == 0 {
+		return messages, nil
+	} else if since.IsTime() && messages[0].Updated > since.Time().Unix() {
+		return messages, nil
+	}
+	return messages[1:], nil // Do not include row with ID itself
 }
 
 func (c *messageCache) MessagesDue() ([]*message, error) {
@@ -536,6 +549,8 @@ func setupCacheDB(db *sql.DB) error {
 		return migrateFrom3(db)
 	} else if schemaVersion == 4 {
 		return migrateFrom4(db)
+	} else if schemaVersion == 5 {
+		return migrateFrom5(db)
 	}
 	return fmt.Errorf("unexpected schema version found: %d", schemaVersion)
 }
@@ -608,5 +623,16 @@ func migrateFrom4(db *sql.DB) error {
 	if _, err := db.Exec(updateSchemaVersion, 5); err != nil {
 		return err
 	}
+	return migrateFrom5(db)
+}
+
+func migrateFrom5(db *sql.DB) error {
+	log.Print("Migrating cache database schema: from 5 to 6")
+	if _, err := db.Exec(migrate5To6AlterMessagesTableQuery); err != nil {
+		return err
+	}
+	if _, err := db.Exec(updateSchemaVersion, 6); err != nil {
+		return err
+	}
 	return nil // Update this when a new version is added
 }
diff --git a/server/server.go b/server/server.go
index 0ef6d89d..e07a647e 100644
--- a/server/server.go
+++ b/server/server.go
@@ -473,8 +473,14 @@ func (s *Server) parsePublishParams(r *http.Request, v *visitor, m *message) (ca
 	}
 	// TODO more restrictions
 	firebase = readBoolParam(r, true, "x-firebase", "firebase")
-	m.Title = readParam(r, "x-title", "title", "t")
-	m.Click = readParam(r, "x-click", "click")
+	title := readParam(r, "x-title", "title", "t")
+	if title != "" {
+		m.Title = title
+	}
+	click := readParam(r, "x-click", "click")
+	if click != "" {
+		m.Click = click
+	}
 	filename := readParam(r, "x-filename", "filename", "file", "f")
 	attach := readParam(r, "x-attach", "attach", "a")
 	if attach != "" || filename != "" {
@@ -514,9 +520,11 @@ func (s *Server) parsePublishParams(r *http.Request, v *visitor, m *message) (ca
 	if messageStr != "" {
 		m.Message = messageStr
 	}
-	m.Priority, err = util.ParsePriority(readParam(r, "x-priority", "priority", "prio", "p"))
+	priority, err := util.ParsePriority(readParam(r, "x-priority", "priority", "prio", "p"))
 	if err != nil {
 		return false, false, "", false, errHTTPBadRequestPriorityInvalid
+	} else if priority > 0 {
+		m.Priority = priority
 	}
 	tagsStr := readParam(r, "x-tags", "tags", "tag", "ta")
 	if tagsStr != "" {
@@ -895,6 +903,13 @@ func parseSince(r *http.Request, poll bool) (sinceMarker, error) {
 		return sinceNoMessages, nil
 	}
 
+	// ID/timestamp
+	parts := strings.Split(since, "/")
+	if len(parts) == 2 && validMessageID(parts[0]) && validUnixTimestamp(parts[1]) {
+		t, _ := toUnixTimestamp(parts[1])
+		return newSince(parts[0], t), nil
+	}
+
 	// ID, timestamp, duration
 	if validMessageID(since) {
 		return newSinceID(since), nil
diff --git a/server/server_firebase_test.go b/server/server_firebase_test.go
index 1fdd8a6e..6abe0db3 100644
--- a/server/server_firebase_test.go
+++ b/server/server_firebase_test.go
@@ -77,6 +77,7 @@ func TestToFirebaseMessage_Message_Normal_Allowed(t *testing.T) {
 	require.Equal(t, map[string]string{
 		"id":                 m.ID,
 		"time":               fmt.Sprintf("%d", m.Time),
+		"updated":            "0",
 		"event":              "message",
 		"topic":              "mytopic",
 		"priority":           "4",
diff --git a/server/server_test.go b/server/server_test.go
index 0827cc90..449c8d37 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -390,6 +390,69 @@ func TestServer_PublishAndPollSince(t *testing.T) {
 	require.Equal(t, 40008, toHTTPError(t, response.Body.String()).Code)
 }
 
+func TestServer_PublishUpdateAndPollSince(t *testing.T) {
+	s := newTestServer(t, newTestConfig(t))
+
+	// Initial PUT
+	response := request(t, s, "PUT", "/mytopic?t=atitle&tags=tag1,tag2&prio=high&click=https://google.com&attach=https://heckel.io", "test 1", nil)
+	message1 := toMessage(t, response.Body.String())
+	require.Equal(t, int64(0), message1.Updated)
+	require.Equal(t, "test 1", message1.Message)
+	require.Equal(t, "atitle", message1.Title)
+	require.Equal(t, 4, message1.Priority)
+	require.Equal(t, []string{"tag1", "tag2"}, message1.Tags)
+	require.Equal(t, "https://google.com", message1.Click)
+	require.Equal(t, "https://heckel.io", message1.Attachment.URL)
+
+	// Update
+	response = request(t, s, "PUT", "/mytopic/"+message1.ID+"?prio=low", "test 2", nil)
+	message2 := toMessage(t, response.Body.String())
+	require.Equal(t, message1.ID, message2.ID)
+	require.True(t, message2.Updated > message1.Updated)
+	require.Equal(t, "test 2", message2.Message) // Updated
+	require.Equal(t, "atitle", message2.Title)
+	require.Equal(t, 2, message2.Priority) // Updated
+	require.Equal(t, []string{"tag1", "tag2"}, message2.Tags)
+	require.Equal(t, "https://google.com", message2.Click)
+	require.Equal(t, "https://heckel.io", message2.Attachment.URL)
+
+	time.Sleep(1100 * time.Millisecond)
+
+	// Another update
+	response = request(t, s, "PUT", "/mytopic/"+message1.ID+"?title=new+title", "test 3", nil)
+	message3 := toMessage(t, response.Body.String())
+	require.True(t, message3.Updated > message2.Updated)
+	require.Equal(t, "test 3", message3.Message)  // Updated
+	require.Equal(t, "new title", message3.Title) // Updated
+
+	// Get all messages: Should be only one that was updated
+	since := "all"
+	response = request(t, s, "GET", "/mytopic/json?since="+since+"&poll=1", "", nil)
+	messages := toMessages(t, response.Body.String())
+	require.Equal(t, 1, len(messages))
+	require.Equal(t, message1.ID, messages[0].ID)
+	require.Equal(t, "test 3", messages[0].Message)
+
+	// Get all messages since "message ID": Should be zero, since we know this message
+	since = message1.ID
+	response = request(t, s, "GET", "/mytopic/json?since="+since+"&poll=1", "", nil)
+	messages = toMessages(t, response.Body.String())
+	require.Equal(t, 0, len(messages))
+
+	// Get all messages since "message ID" but with an older timestamp: Should be the latest updated message
+	since = fmt.Sprintf("%s/%d", message1.ID, message2.Updated) // We're missing an update
+	response = request(t, s, "GET", "/mytopic/json?since="+since+"&poll=1", "", nil)
+	messages = toMessages(t, response.Body.String())
+	require.Equal(t, 1, len(messages))
+	require.Equal(t, "test 3", messages[0].Message)
+
+	// Get all messages since "message ID" with the current timestamp: No messages expected
+	since = fmt.Sprintf("%s/%d", message3.ID, message3.Updated) // We are up-to-date
+	response = request(t, s, "GET", "/mytopic/json?since="+since+"&poll=1", "", nil)
+	messages = toMessages(t, response.Body.String())
+	require.Equal(t, 0, len(messages))
+}
+
 func TestServer_PublishViaGET(t *testing.T) {
 	s := newTestServer(t, newTestConfig(t))
 
diff --git a/server/types.go b/server/types.go
index 0ab357f8..55dc1458 100644
--- a/server/types.go
+++ b/server/types.go
@@ -1,8 +1,10 @@
 package server
 
 import (
+	"errors"
 	"heckel.io/ntfy/util"
 	"net/http"
+	"strconv"
 	"time"
 )
 
@@ -92,11 +94,31 @@ func validMessageID(s string) bool {
 	return util.ValidRandomString(s, messageIDLength)
 }
 
+func validUnixTimestamp(s string) bool {
+	_, err := toUnixTimestamp(s)
+	return err == nil
+}
+
+func toUnixTimestamp(s string) (int64, error) {
+	u, err := strconv.ParseInt(s, 10, 64)
+	if err != nil {
+		return 0, err
+	}
+	if u < 1000000000 || u > 3000000000 { // I know. It's practical. So relax ...
+		return 0, errors.New("invalid unix date")
+	}
+	return u, nil
+}
+
 type sinceMarker struct {
 	time time.Time
 	id   string
 }
 
+func newSince(id string, timestamp int64) sinceMarker {
+	return sinceMarker{time.Unix(timestamp, 0), id}
+}
+
 func newSinceTime(timestamp int64) sinceMarker {
 	return sinceMarker{time.Unix(timestamp, 0), ""}
 }
@@ -117,6 +139,10 @@ func (t sinceMarker) IsID() bool {
 	return t.id != ""
 }
 
+func (t sinceMarker) IsTime() bool {
+	return t.time.Unix() > 0
+}
+
 func (t sinceMarker) Time() time.Time {
 	return t.time
 }