I’m working with a .NET POP3 library to fetch emails from my Gmail account. Right now my approach involves checking the Gmail atom feed first to see how many unread messages there are, then I use the POP3 client to download that same number of messages starting from the beginning.
GmailFeedReader reader = new GmailFeedReader("username", "password");
reader.LoadFeed();
int newCount = reader.UnreadItems.Count;
POP3Handler handler = new POP3Handler("pop.gmail.com", 995, "username", "password", AuthMethod.USERPASS, true);
for (int j = 0; j < newCount; j++)
{
EmailMessage email = handler.RetrieveMessage(j, false);
// process email here
}
I’m wondering if there’s a more efficient method to accomplish this task. Also, once I’ve processed these messages, what’s the proper way to mark them as read so they don’t show up again next time I check for new emails?
Hit this exact problem two years ago building an automated email processor for invoices. POP3 wasn’t designed for selective retrieval - it downloads everything and maybe deletes from the server. Your method has a critical flaw: Gmail’s atom feed shows unread count across all folders, but POP3 only hits the inbox. This creates sync mismatches that will cause duplicate processing or missed emails. I switched to Gmail’s IMAP with IDLE support instead. You can search for unseen messages directly, mark them read after processing, and keep proper state sync. Performance was way better - no more atom feed roundtrips. If you’re stuck with POP3 for compliance, keep a local database of processed Message-IDs. Download all messages, check against your database, process only new ones, then store their Message-IDs. Not pretty, but it works.
Been there. POP3 limitations plus Gmail’s weird quirks make building reliable email processing a nightmare.
You’re mixing protocols that weren’t meant to work together. Gmail’s atom feed and POP3 don’t sync states properly, and you’re stuck writing custom auth, parsing, and state management code.
I hit the same wall at work processing customer emails from multiple Gmail accounts. Weeks debugging duplicate processing and sync issues - total mess.
Switched to automating it with Latenode. Handles Gmail natively and manages read states automatically. Set up workflows that trigger on new emails, process however you want, then mark read or move to folders.
No more POP3 headaches or state tracking. Just drag Gmail nodes, add processing logic, done.
Saved 200+ lines of buggy code and killed all sync issues.
Your approach won’t work - POP3 doesn’t handle read/unread states like IMAP does. When you download messages through POP3, Gmail still thinks they’re unread unless you delete them from the server. So your atom feed count stays the same after processing. I hit this same problem during a corporate email migration. Fixed it by tracking message UIDs or headers locally to identify emails I’d already processed. Just store those identifiers in a database or file and skip the ones you’ve seen before. Better yet, ditch POP3 and use Gmail’s API instead. It handles read/unread management properly and lets you mark messages as read programmatically. That’ll solve your problem without any hacky workarounds.
ya, pop3 can be a hassle. switching to imap will definitely help ya manage read/unread better. plus, you can organize stuff more efficiently. just a thought!