diff --git a/internal/useragent/useragent.go b/internal/useragent/useragent.go
index 23d21074..73da03a3 100644
--- a/internal/useragent/useragent.go
+++ b/internal/useragent/useragent.go
@@ -21,6 +21,7 @@ import (
 	"fmt"
 	"regexp"
 	"runtime"
+	"strings"
 	"sync"
 )
 
@@ -42,9 +43,12 @@ func New() *UserAgent {
 }
 
 func (ua *UserAgent) SetClient(name, version string) {
+	if strings.EqualFold("Mac OS X Notes", name) {
+		return
+	}
+
 	ua.lock.Lock()
 	defer ua.lock.Unlock()
-
 	ua.client = fmt.Sprintf("%v/%v", name, regexp.MustCompile(`(.*) \((.*)\)`).ReplaceAllString(version, "$1-$2"))
 }
 
diff --git a/internal/useragent/useragent_test.go b/internal/useragent/useragent_test.go
index cb915a33..88b102a7 100644
--- a/internal/useragent/useragent_test.go
+++ b/internal/useragent/useragent_test.go
@@ -64,6 +64,14 @@ func TestUserAgent(t *testing.T) {
 			platform: "Windows 10 (10.0)",
 			want:     "Thunderbird/78.6.1 (Windows 10 (10.0))",
 		},
+
+		// We ignore Apple Notes.
+		{
+			name:     "Mac OS X Notes",
+			version:  "4.11",
+			platform: "Windows 10 (10.0)",
+			want:     DefaultUserAgent + " (Windows 10 (10.0))",
+		},
 	}
 
 	for _, test := range tests {
diff --git a/tests/features/imap/id.feature b/tests/features/imap/id.feature
index 9e3db21f..69259477 100644
--- a/tests/features/imap/id.feature
+++ b/tests/features/imap/id.feature
@@ -22,4 +22,29 @@ Feature: The IMAP ID is propagated to bridge
     When user "[user:user]" connects IMAP client "1"
     And IMAP client "1" announces its ID with name "name" and version "version"
     When the user reports a bug
-    Then the header in the "POST" request to "/core/v4/reports/bug" has "User-Agent" set to "name/version ([GOOS])"
\ No newline at end of file
+    Then the header in the "POST" request to "/core/v4/reports/bug" has "User-Agent" set to "name/version ([GOOS])"
+
+  Scenario: User agent re-announces a new ID to IMAP client
+    When user "[user:user]" connects IMAP client "1"
+    And  IMAP client "1" announces its ID with name "name" and version "version"
+    Then the user agent is "name/version ([GOOS])"
+    And  IMAP client "1" announces its ID with name "new_name" and version "new_version"
+    Then the user agent is "new_name/new_version ([GOOS])"
+
+  Scenario: User agent re-announces a new ID to IMAP client and new ID is used for API calls
+    When user "[user:user]" connects IMAP client "1"
+    And  IMAP client "1" announces its ID with name "name" and version "version"
+    When the user reports a bug
+    Then the header in the "POST" request to "/core/v4/reports/bug" has "User-Agent" set to "name/version ([GOOS])"
+    When IMAP client "1" announces its ID with name "new_name" and version "new_version"
+    Then the user agent is "new_name/new_version ([GOOS])"
+    When the user reports a bug
+    Then the header in the "POST" request to "/core/v4/reports/bug" has "User-Agent" set to "new_name/new_version ([GOOS])"
+
+  Scenario: Apple Notes user agent is ignored after IMAP client announces its ID
+    When user "[user:user]" connects IMAP client "1"
+    And  IMAP client "1" announces its ID with name "name" and version "version"
+    Then the user agent is "name/version ([GOOS])"
+    When IMAP client "1" announces its ID with name "Mac OS X Notes" and version "4.11"
+    Then the user agent is "name/version ([GOOS])"
+