Does Google Postmaster Tools domain reputation include subdomains?

Email marketer from Stackoverflow user says root domains are always needed and are the core part of where the reputation is checked.

Email marketer from Sendgrid explains the benefits of dedicated sending domains and subdomains for better control over your sending reputation and improved deliverability.

Email marketer from emailFAQ shares that, in general, subdomains are treated separately from the main domain when it comes to reputation, and it's better to separate sending infrastructure for marketing and transactional emails.

Email marketer from Reddit user explains their experience that subdomains have separate reputations, and recommends using dedicated subdomains for marketing emails.

Email marketer from Mailtrap states that one of the best ways to protect your primary domain’s reputation is to set up a separate subdomain for email sending.

Email marketer from Mailjet suggests that using subdomains can help isolate reputation, which means problems with one subdomain will be less likely to affect the reputation of your main domain.

Email marketer from Gmass says that it is important to warm up your subdomain to build a strong sending reputation.

Marketer from Email Geeks expresses that they're still not totally convinced given GPT is showing a reputation, but nothing sends mail with the org domain.

Marketer from Email Geeks mentions that one of their customers was explicitly told by Google that the reputation of the organisational domain didn’t include anything to do with subdomains.

Marketer from Email Geeks shares they've seen completely different GPT reps for parent domains and subdomains, and they regularly see High GPT reps for domains that haven't started sending email yet, which can change fast when they start.

Expert from Email Geeks shares her assumption that the root domain reputation is a mix of mail with that d= and mail with any d= that is a subdomain.

Expert from Spamresource suggests using subdomains to protect your primary domain’s reputation, especially for different types of email (transactional vs. marketing).

Expert from Email Geeks explains that she generally doesn't think about reputation in terms of the 5322.from domain, and looks harder at the d= when looking at reputation.

Expert from Email Geeks suggests that, based on the FBL identifier, it seems Google is including the subdomain in the root calculation but is separating it out with the FBL identifier.

Expert from Word to the Wise explains the benefit of using subdomains is that it allows you to isolate different types of email traffic and their associated reputation, which can prevent a negative reputation from impacting your core domain.

Documentation from Microsoft says that your domain name is the address that appears after the @ sign in email addresses, and after www. in web addresses.

Documentation from Google Help details that Postmaster Tools provides an overview of your domain's reputation with Google, but doesn't explicitly state whether subdomains are aggregated into the root domain reputation calculation or kept separate.

Documentation from Cloudflare explains the concept of a subdomain as part of a domain name's structure.

Documentation from Google Help clarifies that to see data in Postmaster Tools, you need to authenticate your sending domain using SPF or DKIM.

Documentation from Google Help explains that the data in Google Postmaster Tools is aggregated for domains that have passed Google's authentication checks (SPF, DKIM, DMARC).

Documentation from RFC explains that, each subdomain is a seperate domain, and is treated differently from the top level domain.