How to retrieve Gmail messages using C# programming

Other Questions Gmail
1

I’ve been struggling to fetch email messages from my Gmail account using C#. I’ve attempted multiple libraries and different approaches but haven’t had success with any of them so far.

I’m looking for a working example that demonstrates how to properly authenticate with Gmail and retrieve email messages programmatically. Here’s what I’ve tried:

using System;
using Google.Apis.Gmail.v1;
using Google.Apis.Auth.OAuth2;

public class EmailReader
{
    public void ConnectToGmail()
    {
        // My authentication attempt
        UserCredential credential = GoogleWebAuthorizationBroker.AuthorizeAsync(
            clientSecrets,
            scopes,
            "user",
            CancellationToken.None).Result;
        
        var service = new GmailService();
        // This is where I'm getting stuck
    }
}

Can someone share a complete working solution that shows the authentication process and message retrieval? I just need to read basic email data like sender, subject, and body content.

2

Your code’s missing the service initialization with credentials. You need to pass the credential object to the GmailService constructor. Here’s what fixed it for me:

var service = new GmailService(new BaseClientService.Initializer()
{
    HttpClientInitializer = credential,
    ApplicationName = "YourAppName"
});

For messages, use service.Users.Messages.List() first to get message IDs, then fetch individual messages with service.Users.Messages.Get(). Gmail returns message content in base64 format, so you’ll need to decode it. Also make sure your scopes include “https://www.googleapis.com/auth/gmail.readonly” at minimum. I spent hours debugging auth issues before realizing I had the wrong scope in my Google Console project.

3

Had the same headache with an email automation project last year. Gmail’s the worst because it stores email content in like 5 different formats. Once you get auth working, the real fun starts with parsing message payloads. Body content usually lives in message.Payload.Parts - you’ve got to check MimeType to see if it’s plain text or HTML. Multipart messages? You’re iterating through the parts array hunting for actual content. Here’s what’ll get you: some emails dump the body straight into message.Payload.Body.Data instead of parts. I wrote a recursive function that just brute-forces through the message structure to grab text no matter what format it’s in. Watch out for rate limiting too if you’re processing tons of emails.

4

don’t forget to set up your credentials.json file correctly first - that’s where most people mess up. dl it from google cloud console and put it in your project dir. also make sure the oauth consent screen is configured properly or u’ll get weird auth errors that don’t make sense.