Hi folks! I'm reaching out to see if anyone has insights into a problem we're facing. We're a small IT team of two and have recently set up Exchange Server 2019 to manage our company email. We chose to host it ourselves since using hosted email services was too costly, especially with our FDA regulations requiring a dedicated business email domain. Everything was running smoothly until yesterday, October 23, when we could send and receive emails without a hitch. However, this morning, we discovered that while we can still receive emails and send messages to other Microsoft Exchange domains, we're unable to send emails to external addresses like Gmail or Yahoo. We haven't made any configuration changes overnight, so we're baffled by this sudden issue. So far, we've tried creating a new test account, registering our IP with SpamHaus, and checking the exposed ports (25, 80, 443, 587). Any advice or troubleshooting tips would be greatly appreciated as we aim to get things running correctly!
4 Answers
Another thought — make sure you’re not just getting caught in spam filters. Set up some email hygiene measures because once spammers find your server, they can really mess up your email delivery. Have you thought about implementing additional rules in Exchange Admin Center for handling junk email?
Honestly, self-hosting might not be the best route for a small business, especially with just two of you managing it. The hidden costs and troubleshooting can add up quickly. Have you considered moving to a managed service? It could save you a ton of headaches in the long run!
I hear you on that! A hosted service does sound appealing, but we felt the initial costs were hard to sell to management.
Have you checked your SPF and DNSSEC settings? If those aren’t configured properly, that could lead to delivery problems. Also, it's worth looking at your IP reputation — sometimes even if everything looks okay, emails might still get blocked. And just to clarify, your domain isn't one of those unusual TLDs, right?
We're using Cloudflare for managing our domain (.com). Thanks for the heads up about the SPF and DNSSEC! I ran a check with MXToolbox and found a few errors we're addressing now. Our IP is blacklisted on Barracuda, which we're investigating.
If sending emails has stopped working, you should check the response from the remote mail servers. Are they providing error codes when your emails fail? Check the server logs for more details on the issue. You could also use tools like telnet or Wireshark to diagnose SMTP connections more directly. They can help pinpoint where things are going wrong.
Yes! We’re planning to set up some rules like that, and MXToolbox has been a helpful resource for spotting these kinds of errors.