What are the lists of subdomains for major email providers like Google, Microsoft, Yahoo, and Apple?

Email marketer from Reddit user u/YahooFan123 shares that Yahoo uses subdomains like mail.yahoo.com and currently they do not use rocketmail.com but are more difficult to track comprehensively.

Email marketer from Email Marketing Forum user EmailPro2000 discusses the importance of understanding subdomains for deliverability and provides examples of how providers like Gmail and Outlook use different subdomains for various services.

Email marketer from Email Marketing Tips Blog explains that understanding subdomains can help marketers better segment their email lists and improve targeting.

Email marketer from Email Geeks mentions that a complete list of subdomains is difficult to maintain, but shares a resource for Apple domains: https://www.spamresource.com/2018/04/reference-apple-email-domains.html

Email marketer from StackExchange user TechGuru88 shares that major providers often use numerous subdomains for tracking and security. Provides examples like mail.google.com and outlook.live.com but notes a complete list is hard to compile.

Expert from Spamresource shares a list of Apple email domains, including icloud.com, me.com, and mac.com. Provides the MX records for each domain.

Expert from Email Geeks guesses the email market share is as follows: Gmail 65%, Hotmail 16%, Yahoo 13%, Apple just under 1%, Comcast just under 1%, Everything else 4%. Mentions that Yahoo was growing, and Microsoft was shrinking, last time he looked. Also questions how selling to men may skew the numbers.

Expert from Spamresource provides a reference list of domains used by Microsoft, AOL, Gmail, and Yahoo. This is not exhaustive.

Expert from Email Geeks says a complete list of subdomains is difficult to maintain, but shares that he is about to release a list of the top 10 million domains that are mail hosted by MAGY (Microsoft, Apple, Google, Yahoo).

Expert from Email Geeks mentions that it would be a good idea to make a new master MAGY sheet and will include apple domains. Mentions that this will take some time but until then shares this link to his Apple domain list: https://www.spamresource.com/2018/04/reference-apple-email-domains.html

Documentation from Apple Support explains that iCloud Mail primarily uses icloud.com, me.com, and mac.com domains, but additional subdomains may exist for specific functions. A comprehensive list is not publicly available.

Documentation from Spamresource provides information on domains from Microsoft, AOL and Gmail. The information may be in-complete.

Documentation from Google Workspace Admin Help explains that Gmail uses various subdomains for different functions, including mail.google.com for the web interface and others for specific services, but a comprehensive list is not publicly available.

Documentation from IETF RFC 5321 explains that mail servers use MX records to determine the appropriate subdomain or domain to deliver mail to, highlighting the technical infrastructure behind email routing.

Documentation from Microsoft Support details that Microsoft's email services, including Outlook and Hotmail, use numerous subdomains for various purposes, such as outlook.live.com for the web interface, but does not provide a complete list.