rbm.goog is a domain owned by Google and used by RCS Business Messaging (RBM), the platform through which verified businesses send RCS messages. It appears in the identifiers of business agents, which take the form [email protected], and the domain itself redirects to Google's RCS for Business developer site. It is Google's infrastructure, not a company that is texting you.
Why you are seeing it
Every business that sends RCS through Google's platform has an agent, and every agent has an ID ending in @rbm.goog. Some phones and messaging apps expose that ID in the conversation details, in a notification, or beside the sender name when the brand's own display name has not loaded. People see an address they do not recognise, search for it, and land here. The short answer is that the message travelled through Google's RBM platform, which is exactly what a legitimate verified business message does.
Is a message from rbm.goog safe?
The domain itself is not a warning sign. What tells you whether the sender is genuine is the verification the phone draws from the approved agent record: the business name, logo and checkmark, and a "verified" note in the sender details. A verified sender cannot be imitated by typing a name into a message. If a conversation shows rbm.goog but no verified business identity, treat it as you would any unknown sender, and never enter a password or card number in reply to a text.
For businesses
Your agent ID is assigned when your provider creates the agent in Google's console, before carrier verification. It is stable for the life of the agent and is the address your provider uses when the phone asks Google which business is sending. What is an RBM agent explains the record behind it; RCS waiting for activation covers what happens between creating the agent and the first verified send.