I’m trying to build a C# program that can fetch email messages from my Gmail account. I’ve been searching for working solutions but most of the methods I found online seem outdated. Gmail changed their security settings a while back and now the old approaches don’t work anymore.
I attempted using both POP3 and IMAP protocols but neither worked properly. I also tried using OpenSSL.NET library but it keeps crashing with an assembly loading error. The error says it can’t find ‘ManagedOpenSsl, Version=0.4.3.0’ and mentions something about incorrect format.
I think the OpenSSL issue might be related to DLL file placement. I tried putting libssl32.dll and ssleay32.dll in different folders like /bin directory but still no luck.
What’s the best way to connect to Gmail from C# nowadays? Any working code examples would be really helpful.
honestly the gmail api route is solid but if you’re stuck on imap then mailkit library works great for me. it’s way more reliable than the old openssl stuff you were trying. just enable 2fa on your gmail and generate an app password - that’s the trick most people miss. then use imap.gmail.com port 993 with ssl enabled.
Skip IMAP/POP3 and just use Gmail API - I made this switch last year after hitting the same walls you’re dealing with. OAuth2 actually works, unlike the old credential methods Google killed off. Grab the Google.Apis.Gmail.v1 NuGet package first. Then head to Google Cloud Console for OAuth2 setup - this is where everyone gets tripped up. Enable Gmail API for your project and download the credentials JSON. You’ll need user consent once, then token refresh happens automatically. Google’s C# docs are surprisingly decent once you get through the initial setup mess. The API crushes traditional email protocols for filtering messages and pulling metadata. Watch out for one thing - your OAuth redirect URI has to match your code exactly, including port numbers when testing locally.
Had the same Gmail issues about six months back while updating an old email monitoring app. Those OpenSSL assembly errors are super common with old libraries - honestly, just ditch that approach. It’s a maintenance nightmare. What actually worked: System.Net.Mail with SMTP auth, but you’ve got to set up Gmail’s security first. Turn on two-factor auth in your Google account, then create an app-specific password in account settings. This gets around the newer security stuff without dealing with OAuth. For IMAP, use implicit SSL, not explicit TLS - that one tripped me up. Your connection string needs SSL from the start, don’t try upgrading mid-handshake. Still getting auth failures? Make sure less secure app access is off and you’re using the app password, not your regular Gmail password.
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