diff --git a/server/cache.go b/server/message_cache.go
similarity index 93%
rename from server/cache.go
rename to server/message_cache.go
index 3a35b74..4a48ac1 100644
--- a/server/cache.go
+++ b/server/message_cache.go
@@ -168,12 +168,13 @@ const (
 	`
 )
 
-type sqliteCache struct {
+type messageCache struct {
 	db  *sql.DB
 	nop bool
 }
 
-func newSqliteCache(filename string, nop bool) (*sqliteCache, error) {
+// newSqliteCache creates a SQLite file-backed cache
+func newSqliteCache(filename string, nop bool) (*messageCache, error) {
 	db, err := sql.Open("sqlite3", filename)
 	if err != nil {
 		return nil, err
@@ -181,20 +182,20 @@ func newSqliteCache(filename string, nop bool) (*sqliteCache, error) {
 	if err := setupCacheDB(db); err != nil {
 		return nil, err
 	}
-	return &sqliteCache{
+	return &messageCache{
 		db:  db,
 		nop: nop,
 	}, nil
 }
 
 // newMemCache creates an in-memory cache
-func newMemCache() (*sqliteCache, error) {
+func newMemCache() (*messageCache, error) {
 	return newSqliteCache(createMemoryFilename(), false)
 }
 
 // newNopCache creates an in-memory cache that discards all messages;
 // it is always empty and can be used if caching is entirely disabled
-func newNopCache() (*sqliteCache, error) {
+func newNopCache() (*messageCache, error) {
 	return newSqliteCache(createMemoryFilename(), true)
 }
 
@@ -208,7 +209,7 @@ func createMemoryFilename() string {
 	return fmt.Sprintf("file:%s?mode=memory&cache=shared", util.RandomString(10))
 }
 
-func (c *sqliteCache) AddMessage(m *message) error {
+func (c *messageCache) AddMessage(m *message) error {
 	if m.Event != messageEvent {
 		return errUnexpectedMessageType
 	}
@@ -249,7 +250,7 @@ func (c *sqliteCache) AddMessage(m *message) error {
 	return err
 }
 
-func (c *sqliteCache) Messages(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
+func (c *messageCache) Messages(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
 	if since.IsNone() {
 		return make([]*message, 0), nil
 	} else if since.IsID() {
@@ -258,7 +259,7 @@ func (c *sqliteCache) Messages(topic string, since sinceMarker, scheduled bool)
 	return c.messagesSinceTime(topic, since, scheduled)
 }
 
-func (c *sqliteCache) messagesSinceTime(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
+func (c *messageCache) messagesSinceTime(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
 	var rows *sql.Rows
 	var err error
 	if scheduled {
@@ -272,7 +273,7 @@ func (c *sqliteCache) messagesSinceTime(topic string, since sinceMarker, schedul
 	return readMessages(rows)
 }
 
-func (c *sqliteCache) messagesSinceID(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
+func (c *messageCache) messagesSinceID(topic string, since sinceMarker, scheduled bool) ([]*message, error) {
 	idrows, err := c.db.Query(selectRowIDFromMessageID, topic, since.ID())
 	if err != nil {
 		return nil, err
@@ -298,7 +299,7 @@ func (c *sqliteCache) messagesSinceID(topic string, since sinceMarker, scheduled
 	return readMessages(rows)
 }
 
-func (c *sqliteCache) MessagesDue() ([]*message, error) {
+func (c *messageCache) MessagesDue() ([]*message, error) {
 	rows, err := c.db.Query(selectMessagesDueQuery, time.Now().Unix())
 	if err != nil {
 		return nil, err
@@ -306,12 +307,12 @@ func (c *sqliteCache) MessagesDue() ([]*message, error) {
 	return readMessages(rows)
 }
 
-func (c *sqliteCache) MarkPublished(m *message) error {
+func (c *messageCache) MarkPublished(m *message) error {
 	_, err := c.db.Exec(updateMessagePublishedQuery, m.ID)
 	return err
 }
 
-func (c *sqliteCache) MessageCount(topic string) (int, error) {
+func (c *messageCache) MessageCount(topic string) (int, error) {
 	rows, err := c.db.Query(selectMessageCountForTopicQuery, topic)
 	if err != nil {
 		return 0, err
@@ -329,7 +330,7 @@ func (c *sqliteCache) MessageCount(topic string) (int, error) {
 	return count, nil
 }
 
-func (c *sqliteCache) Topics() (map[string]*topic, error) {
+func (c *messageCache) Topics() (map[string]*topic, error) {
 	rows, err := c.db.Query(selectTopicsQuery)
 	if err != nil {
 		return nil, err
@@ -349,12 +350,12 @@ func (c *sqliteCache) Topics() (map[string]*topic, error) {
 	return topics, nil
 }
 
-func (c *sqliteCache) Prune(olderThan time.Time) error {
+func (c *messageCache) Prune(olderThan time.Time) error {
 	_, err := c.db.Exec(pruneMessagesQuery, olderThan.Unix())
 	return err
 }
 
-func (c *sqliteCache) AttachmentsSize(owner string) (int64, error) {
+func (c *messageCache) AttachmentsSize(owner string) (int64, error) {
 	rows, err := c.db.Query(selectAttachmentsSizeQuery, owner, time.Now().Unix())
 	if err != nil {
 		return 0, err
@@ -372,7 +373,7 @@ func (c *sqliteCache) AttachmentsSize(owner string) (int64, error) {
 	return size, nil
 }
 
-func (c *sqliteCache) AttachmentsExpired() ([]string, error) {
+func (c *messageCache) AttachmentsExpired() ([]string, error) {
 	rows, err := c.db.Query(selectAttachmentsExpiredQuery, time.Now().Unix())
 	if err != nil {
 		return nil, err
diff --git a/server/cache_test.go b/server/message_cache_test.go
similarity index 96%
rename from server/cache_test.go
rename to server/message_cache_test.go
index d768c4b..aea71c7 100644
--- a/server/cache_test.go
+++ b/server/message_cache_test.go
@@ -18,7 +18,7 @@ func TestMemCache_Messages(t *testing.T) {
 	testCacheMessages(t, newMemTestCache(t))
 }
 
-func testCacheMessages(t *testing.T, c *sqliteCache) {
+func testCacheMessages(t *testing.T, c *messageCache) {
 	m1 := newDefaultMessage("mytopic", "my message")
 	m1.Time = 1
 
@@ -92,7 +92,7 @@ func TestMemCache_MessagesScheduled(t *testing.T) {
 	testCacheMessagesScheduled(t, newMemTestCache(t))
 }
 
-func testCacheMessagesScheduled(t *testing.T, c *sqliteCache) {
+func testCacheMessagesScheduled(t *testing.T, c *messageCache) {
 	m1 := newDefaultMessage("mytopic", "message 1")
 	m2 := newDefaultMessage("mytopic", "message 2")
 	m2.Time = time.Now().Add(time.Hour).Unix()
@@ -126,7 +126,7 @@ func TestMemCache_Topics(t *testing.T) {
 	testCacheTopics(t, newMemTestCache(t))
 }
 
-func testCacheTopics(t *testing.T, c *sqliteCache) {
+func testCacheTopics(t *testing.T, c *messageCache) {
 	require.Nil(t, c.AddMessage(newDefaultMessage("topic1", "my example message")))
 	require.Nil(t, c.AddMessage(newDefaultMessage("topic2", "message 1")))
 	require.Nil(t, c.AddMessage(newDefaultMessage("topic2", "message 2")))
@@ -149,7 +149,7 @@ func TestMemCache_MessagesTagsPrioAndTitle(t *testing.T) {
 	testCacheMessagesTagsPrioAndTitle(t, newMemTestCache(t))
 }
 
-func testCacheMessagesTagsPrioAndTitle(t *testing.T, c *sqliteCache) {
+func testCacheMessagesTagsPrioAndTitle(t *testing.T, c *messageCache) {
 	m := newDefaultMessage("mytopic", "some message")
 	m.Tags = []string{"tag1", "tag2"}
 	m.Priority = 5
@@ -170,7 +170,7 @@ func TestMemCache_MessagesSinceID(t *testing.T) {
 	testCacheMessagesSinceID(t, newMemTestCache(t))
 }
 
-func testCacheMessagesSinceID(t *testing.T, c *sqliteCache) {
+func testCacheMessagesSinceID(t *testing.T, c *messageCache) {
 	m1 := newDefaultMessage("mytopic", "message 1")
 	m1.Time = 100
 	m2 := newDefaultMessage("mytopic", "message 2")
@@ -240,7 +240,7 @@ func TestMemCache_Prune(t *testing.T) {
 	testCachePrune(t, newMemTestCache(t))
 }
 
-func testCachePrune(t *testing.T, c *sqliteCache) {
+func testCachePrune(t *testing.T, c *messageCache) {
 	m1 := newDefaultMessage("mytopic", "my message")
 	m1.Time = 1
 
@@ -277,7 +277,7 @@ func TestMemCache_Attachments(t *testing.T) {
 	testCacheAttachments(t, newMemTestCache(t))
 }
 
-func testCacheAttachments(t *testing.T, c *sqliteCache) {
+func testCacheAttachments(t *testing.T, c *messageCache) {
 	expires1 := time.Now().Add(-4 * time.Hour).Unix()
 	m := newDefaultMessage("mytopic", "flower for you")
 	m.ID = "m1"
@@ -467,7 +467,7 @@ func TestMemCache_NopCache(t *testing.T) {
 	assert.Empty(t, topics)
 }
 
-func newSqliteTestCache(t *testing.T) *sqliteCache {
+func newSqliteTestCache(t *testing.T) *messageCache {
 	c, err := newSqliteCache(newSqliteTestCacheFile(t), false)
 	if err != nil {
 		t.Fatal(err)
@@ -479,7 +479,7 @@ func newSqliteTestCacheFile(t *testing.T) string {
 	return filepath.Join(t.TempDir(), "cache.db")
 }
 
-func newSqliteTestCacheFromFile(t *testing.T, filename string) *sqliteCache {
+func newSqliteTestCacheFromFile(t *testing.T, filename string) *messageCache {
 	c, err := newSqliteCache(filename, false)
 	if err != nil {
 		t.Fatal(err)
@@ -487,7 +487,7 @@ func newSqliteTestCacheFromFile(t *testing.T, filename string) *sqliteCache {
 	return c
 }
 
-func newMemTestCache(t *testing.T) *sqliteCache {
+func newMemTestCache(t *testing.T) *messageCache {
 	c, err := newMemCache()
 	if err != nil {
 		t.Fatal(err)
diff --git a/server/server.go b/server/server.go
index ef1c30a..ba8faf8 100644
--- a/server/server.go
+++ b/server/server.go
@@ -45,7 +45,7 @@ type Server struct {
 	mailer       mailer
 	messages     int64
 	auth         auth.Auther
-	cache        *sqliteCache
+	messageCache *messageCache
 	fileCache    *fileCache
 	closeChan    chan bool
 	mu           sync.Mutex
@@ -118,11 +118,11 @@ func New(conf *Config) (*Server, error) {
 	if conf.SMTPSenderAddr != "" {
 		mailer = &smtpSender{config: conf}
 	}
-	cache, err := createCache(conf)
+	messageCache, err := createMessageCache(conf)
 	if err != nil {
 		return nil, err
 	}
-	topics, err := cache.Topics()
+	topics, err := messageCache.Topics()
 	if err != nil {
 		return nil, err
 	}
@@ -149,18 +149,18 @@ func New(conf *Config) (*Server, error) {
 		}
 	}
 	return &Server{
-		config:    conf,
-		cache:     cache,
-		fileCache: fileCache,
-		firebase:  firebaseSubscriber,
-		mailer:    mailer,
-		topics:    topics,
-		auth:      auther,
-		visitors:  make(map[string]*visitor),
+		config:       conf,
+		messageCache: messageCache,
+		fileCache:    fileCache,
+		firebase:     firebaseSubscriber,
+		mailer:       mailer,
+		topics:       topics,
+		auth:         auther,
+		visitors:     make(map[string]*visitor),
 	}, nil
 }
 
-func createCache(conf *Config) (*sqliteCache, error) {
+func createMessageCache(conf *Config) (*messageCache, error) {
 	if conf.CacheDuration == 0 {
 		return newNopCache()
 	} else if conf.CacheFile != "" {
@@ -416,7 +416,7 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 		}()
 	}
 	if cache {
-		if err := s.cache.AddMessage(m); err != nil {
+		if err := s.messageCache.AddMessage(m); err != nil {
 			return err
 		}
 	}
@@ -566,7 +566,7 @@ func (s *Server) handleBodyAsAttachment(r *http.Request, v *visitor, m *message,
 	} else if m.Time > time.Now().Add(s.config.AttachmentExpiryDuration).Unix() {
 		return errHTTPBadRequestAttachmentsExpiryBeforeDelivery
 	}
-	visitorAttachmentsSize, err := s.cache.AttachmentsSize(v.ip)
+	visitorAttachmentsSize, err := s.messageCache.AttachmentsSize(v.ip)
 	if err != nil {
 		return err
 	}
@@ -824,7 +824,7 @@ func (s *Server) sendOldMessages(topics []*topic, since sinceMarker, scheduled b
 		return nil
 	}
 	for _, t := range topics {
-		messages, err := s.cache.Messages(t.ID, since, scheduled)
+		messages, err := s.messageCache.Messages(t.ID, since, scheduled)
 		if err != nil {
 			return err
 		}
@@ -930,7 +930,7 @@ func (s *Server) updateStatsAndPrune() {
 
 	// Delete expired attachments
 	if s.fileCache != nil {
-		ids, err := s.cache.AttachmentsExpired()
+		ids, err := s.messageCache.AttachmentsExpired()
 		if err == nil {
 			if err := s.fileCache.Remove(ids...); err != nil {
 				log.Printf("error while deleting attachments: %s", err.Error())
@@ -942,7 +942,7 @@ func (s *Server) updateStatsAndPrune() {
 
 	// Prune message cache
 	olderThan := time.Now().Add(-1 * s.config.CacheDuration)
-	if err := s.cache.Prune(olderThan); err != nil {
+	if err := s.messageCache.Prune(olderThan); err != nil {
 		log.Printf("error pruning cache: %s", err.Error())
 	}
 
@@ -950,7 +950,7 @@ func (s *Server) updateStatsAndPrune() {
 	var subscribers, messages int
 	for _, t := range s.topics {
 		subs := t.Subscribers()
-		msgs, err := s.cache.MessageCount(t.ID)
+		msgs, err := s.messageCache.MessageCount(t.ID)
 		if err != nil {
 			log.Printf("cannot get stats for topic %s: %s", t.ID, err.Error())
 			continue
@@ -1046,7 +1046,7 @@ func (s *Server) runFirebaseKeepaliver() {
 func (s *Server) sendDelayedMessages() error {
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	messages, err := s.cache.MessagesDue()
+	messages, err := s.messageCache.MessagesDue()
 	if err != nil {
 		return err
 	}
@@ -1062,7 +1062,7 @@ func (s *Server) sendDelayedMessages() error {
 				log.Printf("unable to publish to Firebase: %v", err.Error())
 			}
 		}
-		if err := s.cache.MarkPublished(m); err != nil {
+		if err := s.messageCache.MarkPublished(m); err != nil {
 			return err
 		}
 	}
diff --git a/server/server_test.go b/server/server_test.go
index 69cc3f8..f8098e3 100644
--- a/server/server_test.go
+++ b/server/server_test.go
@@ -863,7 +863,7 @@ func TestServer_PublishAttachment(t *testing.T) {
 	require.Equal(t, content, response.Body.String())
 
 	// Slightly unrelated cross-test: make sure we add an owner for internal attachments
-	size, err := s.cache.AttachmentsSize("9.9.9.9") // See request()
+	size, err := s.messageCache.AttachmentsSize("9.9.9.9") // See request()
 	require.Nil(t, err)
 	require.Equal(t, int64(5000), size)
 }
@@ -892,7 +892,7 @@ func TestServer_PublishAttachmentShortWithFilename(t *testing.T) {
 	require.Equal(t, content, response.Body.String())
 
 	// Slightly unrelated cross-test: make sure we add an owner for internal attachments
-	size, err := s.cache.AttachmentsSize("1.2.3.4")
+	size, err := s.messageCache.AttachmentsSize("1.2.3.4")
 	require.Nil(t, err)
 	require.Equal(t, int64(21), size)
 }
@@ -912,7 +912,7 @@ func TestServer_PublishAttachmentExternalWithoutFilename(t *testing.T) {
 	require.Equal(t, "", msg.Attachment.Owner)
 
 	// Slightly unrelated cross-test: make sure we don't add an owner for external attachments
-	size, err := s.cache.AttachmentsSize("127.0.0.1")
+	size, err := s.messageCache.AttachmentsSize("127.0.0.1")
 	require.Nil(t, err)
 	require.Equal(t, int64(0), size)
 }