From 4b4ac84278fbcc2e95680bcf541620c396f7c89f Mon Sep 17 00:00:00 2001
From: agent-aspose-email-examples
 <agent-aspose-email-examples@users.noreply.github.com>
Date: Tue, 31 Mar 2026 09:03:57 -0400
Subject: [PATCH] Auto commit:
 working-with-exchange-ews-client/manipulate-custom-extended-properties-of-email-messages-programmatically-via-exchange-web-services-ews-api.cs

---
 ...cally-via-exchange-web-services-ews-api.cs | 61 +++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 working-with-exchange-ews-client/manipulate-custom-extended-properties-of-email-messages-programmatically-via-exchange-web-services-ews-api.cs

diff --git a/working-with-exchange-ews-client/manipulate-custom-extended-properties-of-email-messages-programmatically-via-exchange-web-services-ews-api.cs b/working-with-exchange-ews-client/manipulate-custom-extended-properties-of-email-messages-programmatically-via-exchange-web-services-ews-api.cs
new file mode 100644
index 00000000..b3f1582f
--- /dev/null
+++ b/working-with-exchange-ews-client/manipulate-custom-extended-properties-of-email-messages-programmatically-via-exchange-web-services-ews-api.cs
@@ -0,0 +1,61 @@
+using Aspose.Email.Clients.Exchange;
+using System;
+using System.Net;
+using Aspose.Email;
+using Aspose.Email.Clients.Exchange.WebService;
+
+class Program
+{
+    static void Main()
+    {
+        try
+        {
+            // Placeholder credentials – replace with real values or skip execution.
+            string mailboxUri = "https://exchange.example.com/EWS/Exchange.asmx";
+            string username = "user@example.com";
+            string password = "password";
+
+            if (mailboxUri.Contains("example.com"))
+            {
+                Console.Error.WriteLine("Placeholder credentials detected. Skipping EWS operations.");
+                return;
+            }
+
+            // Create the EWS client.
+            try
+            {
+                using (IEWSClient client = EWSClient.GetEWSClient(mailboxUri, username, password))
+                {
+                    // List messages in the Inbox folder.
+                    ExchangeMessageInfoCollection messagesInfo = client.ListMessages(client.MailboxInfo.InboxUri);
+                    if (messagesInfo == null || messagesInfo.Count == 0)
+                    {
+                        Console.WriteLine("No messages found in the Inbox.");
+                        return;
+                    }
+
+                    // Fetch the first message.
+                    string messageUri = messagesInfo[0].UniqueUri;
+                    MailMessage message = client.FetchMessage(messageUri);
+
+                    // Add a custom extended property as a header.
+                    const string customHeaderName = "X-Custom-Property";
+                    const string customHeaderValue = "CustomValue";
+                    message.Headers.Add(customHeaderName, customHeaderValue);
+
+                    // Display the added header.
+                    Console.WriteLine($"Added header: {customHeaderName} = {message.Headers[customHeaderName]}");
+                }
+            }
+            catch (Exception ex)
+            {
+                Console.Error.WriteLine($"EWS operation failed: {ex.Message}");
+                return;
+            }
+        }
+        catch (Exception ex)
+        {
+            Console.Error.WriteLine($"Unexpected error: {ex.Message}");
+        }
+    }
+}