diff --git a/app/src/main/java/eu/faircode/email/FragmentMessages.java b/app/src/main/java/eu/faircode/email/FragmentMessages.java
index 2ca5caf9f9..7fa1c289aa 100644
--- a/app/src/main/java/eu/faircode/email/FragmentMessages.java
+++ b/app/src/main/java/eu/faircode/email/FragmentMessages.java
@@ -4592,7 +4592,7 @@ public class FragmentMessages extends FragmentBase implements SharedPreferences.
                             boolean match = false;
                             List<String> emails = EntityCertificate.getAltSubjectName(cert);
                             for (String email : emails)
-                                if (Objects.equals(sender, email)) {
+                                if (email.equalsIgnoreCase(sender)) {
                                     match = true;
                                     break;
                                 }