Where can I find a list of all mailbox providers and their domains?

Email marketer from StackExchange explains that compiling a full list of email domains is an impossible task, and suggests focusing on largest domains and using DNS queries to determine email acceptance on a case-by-case basis. Mentions that many domains use external services so MX records are not a good way of figuring out the details.

Email marketer from Reddit shares that maintaining a list is difficult, and suggests scraping MX records using tools or scripts but to do it ethically and with respect to rate limits. Also warns that you might need to keep the lists yourself

Email marketer from Litmus explains that it's not about having a static list, but more about actively monitoring and segmenting based on engagement. Tools like email analytics can help identify recipient domains, and further segmentation can be based on engagement metrics per domain.

Marketer from Email Geeks notes that no list can be complete, because they alone serve mail for thousands of domains.

Marketer from Email Geeks shares that sometimes even if someone is using Yahoo as the web UI, there is sometimes another layer of filtering (example, some AT&T domains).

Email marketer from GMass recommends building your own custom list, because a pre-built list will be out of date quickly. Build this by extracting the domains from your own lists, or purchased leads.

Email marketer from Email on Acid explains that building a domain list needs constant maintenance but one approach is to start with a seed list of major ISPs and then supplement this by monitoring bounce-back messages to capture unrecognized domains that are actually valid recipients.

Email marketer from Mailchimp shares that whilst they do not provide a comprehensive list of all email domains, they recommend segmenting your audience and tracking engagement by domain to identify which domains are most active and responsive. They suggest using their reporting tools to achieve this.

Email marketer from Neil Patel's blog shares that a comprehensive list is hard to maintain due to constant changes, but suggests focusing on the major players like Gmail, Yahoo, Outlook and AOL. He advises to look at their respective postmaster pages for up-to-date info and domain specifics.

Email marketer from Quora mentions that instead of trying to find the full list (hard to do), segment your existing customers by the domain to figure out who the main mailbox providers are.

Marketer from Email Geeks shares that mailbox providers change and for example Cox is about to become part of Yahoo.

Expert from Word to the Wise (Laura Atkins) emphasizes that a complete, static list of email domains is impossible to maintain. Instead, she advises focusing on monitoring your own sending data to identify the domains your recipients are using and segmenting your lists accordingly. She highlights the importance of using feedback loops and other monitoring tools to identify and address deliverability issues with specific domains.

Expert from Email Geeks explains that with Yahoo, Google, and Microsoft’s corporate offerings and also lots of legacy, absorbed, consolidated and acquired domains, the best such a system could hope for would be to tell you is who answers when you knock.

Expert from Email Geeks shares that you'd pretty much have to build your own list of mailbox providers, evolving with each send.

Expert from Email Geeks mentions that he keeps thinking about making his own free API to say is a domain a free/webmail domain, because other options are mostly ignored or have bad data or want money for something so simple.

Expert from Email Geeks shares that when he started searching for and caching SMTP banners based on what answers, he got threatened and reported as an abuser, and recommends doing it based on DNS instead, unless you have the big iron mail sending happening with enough volume to just grab it from there and save it.

Expert from Spam Resource (Steve Linford) explains that collecting and maintaining a comprehensive list of email domains is a constantly evolving task. He recommends focusing on the major ISPs and understanding their specific sending policies and authentication requirements. He also suggests monitoring bounce messages to identify new and emerging domains.

Documentation from Google Postmaster Tools provides guidelines for bulk email senders and includes information about Google's email infrastructure. While it doesn't offer a full list, it provides insights into how Google handles email and the domains they use.

Documentation from MXToolbox explains how to use their tools to look up MX records for specific domains. While they don't provide a full list, their tools can be used to identify the mail servers (and thus, potentially, the email providers) for given domains.

Documentation from RFC provides the standards used on the internet for email deliverability. It might be helpful to read up on this to understand how email is passed and managed. Note this does not provide a simple list.

Documentation from IANA (Internet Assigned Numbers Authority) explains that they maintain the root zone database, which contains information about top-level domains (TLDs). While it doesn't list all email providers, it provides a list of all valid domain extensions, which is a starting point for identifying potential email domains.

Documentation from Microsoft's Outlook.com Sender Support provides information and best practices for sending emails to Outlook.com and associated domains. This resource outlines their specific domain policies and technical specifications.