Maximum size for reformatting

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

@@ -236,6 +236,8 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
     private static final ExecutorService executor =
             Helper.getBackgroundExecutor(2, "differ");
 
+    private static final int LARGE_MESSAGE_SIZE = 250 * 1024;
+
     // https://github.com/newhouse/url-tracking-stripper
     private static final List<String> PARANOID_QUERY = Collections.unmodifiableList(Arrays.asList(
             "utm_source",
@@ -1606,6 +1608,9 @@ public class AdapterMessage extends RecyclerView.Adapter<AdapterMessage.ViewHold
 
                         return document.html();
                     } else {
+                        if (body.length() > LARGE_MESSAGE_SIZE)
+                            return HtmlHelper.fromHtml("<em>" + context.getString(R.string.title_too_large) + "</em>");
+
                         // Cleanup message
                         document = HtmlHelper.sanitize(context, body, show_images, true);
 

app/src/main/res/values/strings.xml

@@ -670,6 +670,7 @@
     <string name="title_no_format">The originally received message will be included</string>
     <string name="title_no_image">Image could not be decoded</string>
     <string name="title_no_search">Search on server is not available for this account</string>
+    <string name="title_too_large">Message too large to reformat, try to use the original message view via the full screen icon instead</string>
     <string name="title_unused_inline">Unused inline images will be removed on send</string>
     <string name="title_accross_remark">Messages moved across accounts will be downloaded again resulting in extra data usage</string>
     <string name="title_raw_saved">Raw message saved</string>