diff --git a/app/src/main/java/eu/faircode/email/ContactInfo.java b/app/src/main/java/eu/faircode/email/ContactInfo.java
index 31b9b6ba8f..1ed38f85f1 100644
--- a/app/src/main/java/eu/faircode/email/ContactInfo.java
+++ b/app/src/main/java/eu/faircode/email/ContactInfo.java
@@ -501,7 +501,8 @@ public class ContactInfo {
                         "Connection closed by peer".equals(ex.getMessage())) ||
                 (ex instanceof SSLHandshakeException &&
                         ex.getMessage() != null &&
-                        ex.getMessage().contains("usually a protocol error")) ||
+                        (ex.getMessage().contains("usually a protocol error") ||
+                                ex.getMessage().contains("Unacceptable certificate"))) ||
                 (ex instanceof SSLHandshakeException &&
                         (ex.getCause() instanceof SSLProtocolException ||
                                 ex.getCause() instanceof CertificateException ||