t-mobile-bounty-scope/
│
├── t-mobile.com ← own apps · MERGED (single Entra tenant)
│ ├── account.t-mobile.com Entra / Azure AD · edge Akamai
│ ├── *.docs.t-mobile.com ×24 Entra — MS "Sign in" page
│ ├── alm · billerdirect ·
│ │ dealerorder · phys-access Azure AD App Proxy (msappproxy.net)
│ └── sts.t-mobile.com ADFS — legacy fed · on-net, no CDN
│
├── metrobyt-mobile.com ← MetroPCS · folded into T-Mobile prepaid
│
├── sprint.com ← Sprint (merged 2020) · NOT merged
│ ├── idam.sprintdrive.sprint.com OAuth · still issuing, 5 yrs on
│ ├── autodiscover.sprint.com Exchange autodiscover · Outlook
│ └── assurancewireless.com Lifeline prepaid · via Sprint
│
├── uscellular.com / uscc.com ← US Cellular (acq. 2024) · NOT merged
│ ├── login.uscellular.com SAML /idp/SSO.saml2 · Cloudflare
│ └── login-sqa.uscellular.com QA SAML, public · same edge as prod
│
└── blis.com + *.audience.com ×7 ← T-Mobile Advertising / Blis
├── imply.t-ads.blis.com Imply login · T-Mobile Ads
└── imply.publicis.blis.com Imply login · Publicis agency
T-Mobile's own apps merged onto one Entra tenant; the companies it bought each kept their own IdP on their own edge, still running side by side. Sprint's identity service is still issuing OAuth flows five years after the merger, and autodiscover.sprint.com still answers with an Outlook title.