Oddities in Gmail delivery - Adaptive Filters

I don’t know about you, but I’ve been pretty spoiled with a great email client (Gmail) and how it handles the spam that comes through my mailbox. It’s rare it ever gets to my Inbox, and I monitor my Spam folder periodically to make sure no legitimate mail gets there, and it rarely does. I would say this is magic, but, I know better. Gmail takes very good care of its users, like, impeccable care. But, there’s always an expense, and in this case it’s at the expense of the sender.

We’ve dealt with ISPs for years, and it’s a known fact that Gmail is NOT sender-friendly. But, it’s also reported that Gmail doesn’t throw out emails. Well, unfortunately we’re starting to think that’s not really true.

Our customers need to create a Sender Signature to use Postmark. Basically, we just require that you verify the From email you are sending from. This way we are sure you are a real company, but also that you are receiving email there (better for delivery). Well, we were starting to get rare reports of emails not showing up. Not in the Inbox, and not in the Spam folder. It was weird.

We began investigating, and couldn’t figure it out ouselves. The exact same email was getting to one Gmail account, but just disappearing from another. We contacted some outside consultants, and they also didn’t know. But they suggested something that I didn’t think of. Gmail uses adaptive filtering, where they start marking things as Spam based on what you marked as spam in the past. So the cure was adding the From address to the contact list. And it worked, email immediately showed up.

So, I quickly became a stronger believer in asking your users to add your From address to their address book. While this shouldn’t be required, it’s one of these oddities we’ve discovered at least with sending to Gmail. We’ve always said content and reputation should get you to the Inbox, but unfortunately it’s not so black and white.