Microsoft OLC/Hotmail Domains List (Updated for 2025)
Here it is, the first episode of "Fun with Data" for 2025. Today, I present to you a link to a downloadable list containing the top Microsoft Outlook.com (Microsoft OLC / Hotmail) email domains. Why would you need this? Maybe you run some certain mail server (MTA -- mail transfer agent) software that can't group domains based on MX. Maybe you'd like to roll up your subscriber data based on domain to determine what percentage of your subscribers' mailboxes are hosted by Microsoft. Or maybe you're just a nerd like me who thinks domain MX data provides an interesting snapshot into who hosts what mail for which domains.
I've categorized domains thusly:
Microsoft OLC/Outlook.com/Hotmail: Domains that appear to host mail for Microsoft OLC (Outlook Consumer, what was once called Hotmail and is now typically referred to as Outlook.com) subscribers.
Microsoft Corporate: Brands and companies seemingly owned by Microsoft.
This data is sourced starting from online lists of the top one million and top ten million domains, combined with a dash of my own knowledge and historical tracking of Microsoft domains over time.
I am not intentionally including domains with mail hosted by Microsoft 365, Microsoft's B2B email platform.
As I measure this by where a domain's MX record points, there could be a few random "garbage domains" in here, where somebody has misconfigured their domain's MX record in DNS to point at one of these MXes, even though Microsoft may not accept mail for that domain.
Here it is, the first episode of "Fun with Data" for 2025. Today, I present to you a link to a downloadable list containing the top Microsoft Outlook.com (Microsoft OLC / Hotmail) email domains. Why would you need this? Maybe you run some certain mail server (MTA -- mail transfer agent) software that can't group domains based on MX. Maybe you'd like to roll up your subscriber data based on domain to determine what percentage of your subscribers' mailboxes are hosted by Microsoft. Or maybe you're just a nerd like me who thinks domain MX data provides an interesting snapshot into who hosts what mail for which domains.
I've categorized domains thusly:
This data is sourced starting from online lists of the top one million and top ten million domains, combined with a dash of my own knowledge and historical tracking of Microsoft domains over time.
I am not intentionally including domains with mail hosted by Microsoft 365, Microsoft's B2B email platform.
As I measure this by where a domain's MX record points, there could be a few random "garbage domains" in here, where somebody has misconfigured their domain's MX record in DNS to point at one of these MXes, even though Microsoft may not accept mail for that domain.
Corrections welcome; drop me a line as needed.
Comments
Post a Comment
Comments policy: Al is always right. Kidding, mostly. Be polite, please and thank you.