I’m having trouble with my event registration emails getting filtered as spam by Microsoft email services like Outlook and Hotmail. I’m using Mailgun as my email service provider to send confirmation emails when people sign up for events. Even though I’ve configured SPF and DKIM authentication records properly, the emails still end up in the spam folder instead of the inbox. These are legitimate transactional emails that users expect to receive after completing their registration. Has anyone else faced this issue and found a solution?
EmailClient emailService = EmailClient.getInstance();
emailService.authenticate("api", "YOUR_API_TOKEN");
EmailResource resource = emailService.getResource("EMAIL_SERVICE_URL");
FormDataMap emailData = new FormDataMap();
emailData.put("sender", "[email protected]");
emailData.put("recipient", "[email protected]");
emailData.put("title", "John, your event registration is confirmed");
emailData.put("htmlContent", "<h2>Hi John! Your registration for the workshop has been confirmed</h2>");
emailData.put("plainText", "Hi John! Your registration for the workshop has been confirmed");
HttpResponse response = resource.setContentType(MediaType.FORM_URLENCODED)
.send(HttpResponse.class, emailData);
int responseCode = response.getStatusCode();
if (responseCode >= 400) {
throw new EmailDeliveryException("Failed to deliver registration email");
}
Microsoft’s gotten way more aggressive with event emails lately. What really helped my deliverability was switching to double opt-in. Don’t send the full event details right after someone registers - send a bare-bones confirmation email first asking them to verify their address. This plain email gets through way better since there’s nothing to trigger their filters. After they confirm, the second email with all the event info performs much better because Microsoft sees they engaged with the first one. Keep that verification email super plain - just basic text with a confirmation link. No fancy formatting or marketing speak at all. This two-step approach boosted my delivery rates about 40% for Microsoft addresses.
honestly, microsoft’s anti-spam has gotten way worse lately. i had the same issue with my app - try adding a custom “list-unsubscribe” header even tho it’s transactional mail. also check if your from address domain matches your authenticated domain exactly. mismatches kill deliverability fast.
hey, maybe try changing up the wording in your emails a bit? sometimes, overly sales-y language can send em straight to spam. and a solid domain reputation is key too. good luck!
Beyond just SPF and DKIM, implementing DMARC policies can significantly improve your email deliverability since Microsoft scrutinizes these settings closely. I encountered the same issue with my transactional emails until I established a proper DMARC record that included at least a quarantine policy. Additionally, it’s wise to gradually warm up your sending domain rather than sending high volumes immediately, as Microsoft can be quite harsh on new or low-volume domains. It also helps to ensure that your reply-to address aligns with your sender domain and include an unsubscribe link, even in transactional emails. Lastly, remember that the reputation of your sending IP is crucial with Microsoft, so if you’re using Mailgun’s shared IP, consider upgrading to a dedicated one once you reach a sufficient sending volume.
Yeah, this is a nightmare that’s way more complicated than it needs to be. Been there with event notifications - manually tweaking DNS records and crossing your fingers that Microsoft cooperates is brutal.
What finally fixed it for me? Automating the whole email pipeline. Forget wrestling with Mailgun’s API and all those auth headaches - I built an automation that handles everything.
It watches delivery rates live and switches sending strategies based on who you’re emailing. Microsoft addresses? It tweaks content, timing, and sender rep automatically. DMARC compliance happens without me touching anything.
Best part is the learning. Someone opens an email? It remembers what worked. Emails hit spam? It changes tactics for similar people next time.
Now it runs itself. No spam folder checking, no manual settings. Just emails that actually land in inboxes.
Microsoft’s really strict about content filtering and engagement metrics. Here’s what worked for me - avoid words like “confirmed” or “registration” in subject lines since they trigger filters. Try “Event details for John” or “Your workshop information” instead. Also double-check you’re including proper authentication headers in your API calls. For Mailgun, set your tracking parameters correctly and use their reputation dashboard to watch your sender score. The biggest game-changer was getting users to add my sender address to their contacts right after they register. Just add that instruction to your confirmation page. When users actually open and interact with your emails, it gradually improves your reputation with Microsoft’s algorithms.