Why Are My Transactional Emails Going to Spam in Outlook/Hotmail?

If you're sending transactional emails and they keep landing in Outlook's spam folder, the issue likely isn't your content—it's your infrastructure and configuration.

Microsoft Outlook, including Hotmail, Live, and MSN, uses AI-enhanced filters powered by real-time feedback, reputation scoring, geographic routing, and content fingerprinting. These filters don’t just scan your message - they judge your entire sending identity: IP, domain, routing path, and even engagement signals.

Most email platforms offer a static infrastructure: one IP, one relay, one chance.

That’s not enough.

Lemon Email was built for inbox placement, not just sending.

Our proprietary Adaptive Waterfall Routing (AWR) does the heavy lifting:

• We pre-scan recipient domains to analyze their DNS and MX behavior.

• We identify the delivery infrastructure most likely to land in the inbox for that domain and region.

• We route accordingly - dynamically, per-email, per-send.

This matters because Microsoft’s infrastructure is regionally segmented. If your email lands on a mailbox in Frankfurt but originates from a US East Coast IP, expect higher scrutiny.

 Lemon Email detects *.prod.outlook.com hostnames, like EURP194 for Europe or NAMPRD22 for North America, and uses this data to align routing by geography.

We also embed feedback loop monitoring via Microsoft’s SNDS and JMRP tools, allowing us to instantly react to deliverability changes. This lets us isolate poor performing routes and shift traffic proactively.

Here’s the truth: Outlook scoring systems factor in not just who you are - but where you send from, how consistently you do it, and what recipients do with your message. Inbox placement is earned.

Other ESPs advise you to delete “unengaged” contacts. That’s their way of saying: “We don’t know how to deliver to these inboxes.”

Lemon Email doesn’t delete contacts - you paid for them. We get them seen.

So if your transactional emails are disappearing into Outlook’s void, it’s not your message. It’s your method.

Lemon fixes that.

Intelligently, adaptively, and automatically.