Always fallback to connecting to IP addresses

app/src/main/java/eu/faircode/email/MailService.java

@@ -149,12 +149,14 @@ public class MailService implements AutoCloseable {
             //    throw new MailConnectException(new SocketConnectException("Debug", new Exception(), host, port, 0));
             _connect(context, host, port, user, password);
         } catch (MailConnectException ex) {
-            if (this.insecure)
             try {
+                // Some devices resolve IPv6 addresses while not having IPv6 connectivity
+                this.properties.put("mail." + this.protocol + ".ssl.checkserveridentity", "false");
                 InetAddress[] iaddrs = InetAddress.getAllByName(host);
                 if (iaddrs.length > 1)
                     for (InetAddress iaddr : iaddrs)
                         try {
+                            Log.i("Falling back to " + iaddr.getHostAddress());
                             _connect(context, iaddr.getHostAddress(), port, user, password);
                             return;
                         } catch (MessagingException ex1) {