Add canSend function to check mail sending capability

example/lib/main.dart

@@ -28,6 +28,7 @@ class EmailSender extends StatefulWidget {
 class _EmailSenderState extends State<EmailSender> {
   List<String> attachments = [];
   bool isHTML = false;
+  final _canSend = FlutterEmailSender.canSend();
 
   final _recipientController = TextEditingController(
     text: 'example@example.com',
@@ -73,9 +74,18 @@ class _EmailSenderState extends State<EmailSender> {
       appBar: AppBar(
         title: Text('Plugin example app'),
         actions: <Widget>[
-          IconButton(
-            onPressed: send,
-            icon: Icon(Icons.send),
+          FutureBuilder<bool>(
+            future: _canSend,
+            builder: (context, snapshot) {
+              if (!snapshot.hasData || snapshot.data == false) {
+                return const SizedBox();
+              }
+
+              return IconButton(
+                onPressed: send,
+                icon: Icon(Icons.send),
+              );
+            },
           )
         ],
       ),

ios/Classes/SwiftFlutterEmailSenderPlugin.swift

@@ -15,10 +15,17 @@ public class SwiftFlutterEmailSenderPlugin: NSObject, FlutterPlugin {
         switch call.method {
         case "send":
             sendMail(call, result: result)
+        case "canSend":
+            canSend(call, result: result)
         default:
             result(FlutterMethodNotImplemented)
         }
     }
+
+    private func canSend(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
+        let canSend = MFMailComposeViewController.canSendMail();
+        result(canSend)
+    }
 
     private func sendMail(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
         guard let email = parseArgs(call, result: result) else { return }

lib/flutter_email_sender.dart

@@ -1,4 +1,5 @@
 import 'dart:async';
+import 'dart:io';
 
 import 'package:flutter/services.dart';
 
@@ -9,6 +10,14 @@ class FlutterEmailSender {
   static Future<void> send(Email mail) {
     return _channel.invokeMethod('send', mail.toJson());
   }
+
+  static Future<bool> canSend() async {
+    if (Platform.isIOS) {
+      return await _channel.invokeMethod('canSend');
+    }
+
+    return true;
+  }
 }
 
 class Email {
@@ -19,6 +28,7 @@ class Email {
   final String body;
   final List<String>? attachmentPaths;
   final bool isHTML;
+
   Email({
     this.subject = '',
     this.recipients = const [],
@@ -41,3 +51,9 @@ class Email {
     };
   }
 }
+
+extension EmailExt on Email {
+  Future<void> send() {
+    return FlutterEmailSender.send(this);
+  }
+}