diff --git a/app/src/main/java/eu/faircode/email/AdapterMessage.java b/app/src/main/java/eu/faircode/email/AdapterMessage.java
index e40c98d85b..01c76262f9 100644
--- a/app/src/main/java/eu/faircode/email/AdapterMessage.java
+++ b/app/src/main/java/eu/faircode/email/AdapterMessage.java
@@ -606,7 +606,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                                 ImageSpan[] image = buffer.getSpans(off, off, ImageSpan.class);
                                 if (image.length > 0 && image[0].getSource() != null) {
                                     Uri uri = Uri.parse(image[0].getSource());
-                                    if ("http".equals(uri.getScheme()) || "https".equals(uri.getScheme())) {
+                                    if (UriHelper.isHyperLink(uri)) {
                                         ripple(event);
                                         if (onOpenLink(uri, null, false))
                                             return true;
@@ -5855,7 +5855,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                 String host = guri.getHost();
 
                 boolean confirm_link =
-                        !"https".equals(scheme) || TextUtils.isEmpty(host) ||
+                        !"https".equalsIgnoreCase(scheme) || TextUtils.isEmpty(host) ||
                                 prefs.getBoolean(host + ".confirm_link", true);
                 if (always_confirm || (confirm_links && confirm_link)) {
                     Bundle args = new Bundle();
@@ -5914,7 +5914,7 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
                     }
                 }.execute(context, owner, args, "view:cid");
 
-            else if ("http".equals(scheme) || "https".equals(scheme))
+            else if ("http".equalsIgnoreCase(scheme) || "https".equalsIgnoreCase(scheme))
                 onOpenLink(uri, null, false);
 
             else if ("data".equals(scheme))
diff --git a/app/src/main/java/eu/faircode/email/FragmentDialogOpenLink.java b/app/src/main/java/eu/faircode/email/FragmentDialogOpenLink.java
index 1058b7559e..803309a76e 100644
--- a/app/src/main/java/eu/faircode/email/FragmentDialogOpenLink.java
+++ b/app/src/main/java/eu/faircode/email/FragmentDialogOpenLink.java
@@ -499,7 +499,7 @@ public class FragmentDialogOpenLink extends FragmentDialogBase {
 
         cbNotAgain.setText(context.getString(R.string.title_no_ask_for_again, uri.getHost()));
         cbNotAgain.setVisibility(
-                "https".equals(uri.getScheme()) && !TextUtils.isEmpty(uri.getHost())
+                UriHelper.isSecure(uri) && !TextUtils.isEmpty(uri.getHost())
                         ? View.VISIBLE : View.GONE);
 
         setMore(false);
@@ -520,7 +520,7 @@ public class FragmentDialogOpenLink extends FragmentDialogBase {
                             PackageManager pm = context.getPackageManager();
                             Intent intent = new Intent(Intent.ACTION_VIEW)
                                     .addCategory(Intent.CATEGORY_BROWSABLE)
-                                    .setData(uri);
+                                    .setData(UriHelper.fix(uri));
 
                             ResolveInfo main = pm.resolveActivity(intent, 0);
                             if (main != null) {
@@ -659,7 +659,7 @@ public class FragmentDialogOpenLink extends FragmentDialogBase {
                         // https://developer.android.com/training/basics/intents/sending#AppChooser
                         Uri uri = Uri.parse(etLink.getText().toString());
                         Log.i("Open link with uri=" + uri);
-                        Intent view = new Intent(Intent.ACTION_VIEW, uri);
+                        Intent view = new Intent(Intent.ACTION_VIEW, UriHelper.fix(uri));
                         Intent chooser = Intent.createChooser(view, context.getString(R.string.title_select_app));
                         try {
                             startActivity(chooser);
@@ -719,7 +719,7 @@ public class FragmentDialogOpenLink extends FragmentDialogBase {
             if (scheme != null) {
                 int index = text.indexOf(scheme);
                 if (index >= 0)
-                    if ("http".equals(scheme)) {
+                    if ("http".equalsIgnoreCase(scheme)) {
                         ssb.setSpan(new ForegroundColorSpan(colorWarning),
                                 index, index + scheme.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
                         ssb.setSpan(new StyleSpan(Typeface.BOLD),
diff --git a/app/src/main/java/eu/faircode/email/Helper.java b/app/src/main/java/eu/faircode/email/Helper.java
index dbd8790b6b..5be79d5182 100644
--- a/app/src/main/java/eu/faircode/email/Helper.java
+++ b/app/src/main/java/eu/faircode/email/Helper.java
@@ -888,7 +888,7 @@ public class Helper {
 
     static void view(Context context, Intent intent) {
         Uri uri = intent.getData();
-        if ("http".equals(uri.getScheme()) || "https".equals(uri.getScheme()))
+        if (UriHelper.isHyperLink(uri))
             view(context, intent.getData(), false);
         else
             try {
@@ -924,7 +924,9 @@ public class Helper {
                 " isInstalled=" + isInstalled(context, open_with_pkg) +
                 " hasCustomTabs=" + hasCustomTabs(context, uri, open_with_pkg));
 
-        if (!UriHelper.isHyperLink(uri)) {
+        if (UriHelper.isHyperLink(uri))
+            uri = UriHelper.fix(uri);
+        else {
             open_with_pkg = null;
             open_with_tabs = false;
         }
diff --git a/app/src/main/java/eu/faircode/email/UriHelper.java b/app/src/main/java/eu/faircode/email/UriHelper.java
index a07c83852a..1eccefbc82 100644
--- a/app/src/main/java/eu/faircode/email/UriHelper.java
+++ b/app/src/main/java/eu/faircode/email/UriHelper.java
@@ -338,7 +338,7 @@ public class UriHelper {
         } else
             url = uri;
 
-        if (url.isOpaque() || !UriHelper.isHyperLink(url))
+        if (url.isOpaque() || !isHyperLink(url))
             return uri;
 
         Uri.Builder builder = url.buildUpon();
@@ -402,12 +402,24 @@ public class UriHelper {
     }
 
     static boolean isSecure(Uri uri) {
-        return (!uri.isOpaque() && "https".equals(uri.getScheme()));
+        return (!uri.isOpaque() && "https".equalsIgnoreCase(uri.getScheme()));
     }
 
     static boolean isHyperLink(Uri uri) {
         return (!uri.isOpaque() &&
-                ("http".equals(uri.getScheme()) || "https".equals(uri.getScheme())));
+                ("http".equalsIgnoreCase(uri.getScheme()) ||
+                        "https".equalsIgnoreCase(uri.getScheme())));
+    }
+
+    static Uri fix(Uri uri) {
+        if ("HTTP".equals(uri.getScheme()) || "HTTPS".equals(uri.getScheme())) {
+            String u = uri.toString();
+            int semi = u.indexOf(':');
+            if (semi > 0)
+                return Uri.parse(u.substring(0, semi).toLowerCase(Locale.ROOT) + u.substring(semi));
+        }
+
+        return uri;
     }
 
     static void test(Context context) {