updating buildgradle to use 26 in order to support newer versions of RN

android/build.gradle

@@ -1,8 +1,8 @@
 apply plugin: 'com.android.library'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "23.0.1"
+    compileSdkVersion 26
+    buildToolsVersion "26.0.3"
 
     defaultConfig {
         minSdkVersion 16

android/src/main/java/com/reactlibrary/mailcompose/RNMailComposeModule.java

@@ -4,7 +4,9 @@
 import android.content.ActivityNotFoundException;
 import android.content.Intent;
 import android.net.Uri;
+import android.os.Build;
 import android.os.Bundle;
+import android.support.v4.content.FileProvider;
 import android.text.Html;
 import android.text.Spanned;
 import android.util.Base64;
@@ -35,7 +37,7 @@
 
 
 public class RNMailComposeModule extends ReactContextBaseJavaModule {
-    private static final int ACTIVITY_SEND = 129382;
+    private static final int ACTIVITY_SEND = 29382;
 
     private Promise mPromise;
 
@@ -123,7 +125,16 @@ private void addAttachments(Intent intent, ReadableArray attachments) {
                     }
 
                     if (tempFile != null) {
-                        uris.add(Uri.fromFile(tempFile));
+                        if (Build.VERSION.SDK_INT > Build.VERSION_CODES.M) {
+                            Uri apkURI = FileProvider.getUriForFile(
+                                    getReactApplicationContext(),
+                                    getReactApplicationContext().getApplicationContext()
+                                            .getPackageName() + ".provider", tempFile);
+                            intent.setDataAndType(apkURI, "image/*");
+                            uris.add(apkURI);
+                        } else {
+                            uris.add(Uri.fromFile(tempFile));
+                        }
                     }
                 }
             }

ios/RNMailCompose/RNMailCompose.swift

@@ -134,5 +134,10 @@ class RNMailCompose: NSObject, MFMailComposeViewControllerDelegate {
     }
     return false
   }
+
+    @objc
+    static func requiresMainQueueSetup() -> Bool {
+        return false
+    }
 }