diff --git a/src/crates/services/miniapp-market-service/README.md b/src/crates/services/miniapp-market-service/README.md
index 55470cc63f..19e363a2a8 100644
--- a/src/crates/services/miniapp-market-service/README.md
+++ b/src/crates/services/miniapp-market-service/README.md
@@ -193,6 +193,9 @@ then run `cargo test -p openbitfun-miniapp-market-service --lib email_auth::test
 and a real message render check after SMTP/template changes.
 
 Marketplace author labels are public: email accounts display their full verified
-email address in `user.login`, listing owners, and moderation submitters. GitHub
+email address in listing owners and moderation submitters. The authenticated
+`/me` profile keeps its legacy `user.login` protocol handle and exposes the
+verified address separately as `email`; older relays require that handle format.
+Skin uses the separate email for its public author projection. GitHub
 accounts retain their GitHub login. Ownership and authorization use internal IDs,
 never the displayed label; this does not link email and GitHub accounts.
diff --git a/src/crates/services/miniapp-market-service/src/db.rs b/src/crates/services/miniapp-market-service/src/db.rs
index 4bf2ce8dc9..3708ee2d6b 100644
--- a/src/crates/services/miniapp-market-service/src/db.rs
+++ b/src/crates/services/miniapp-market-service/src/db.rs
@@ -312,9 +312,9 @@ fn user_from_row(row: sqlx::sqlite::SqliteRow) -> AuthenticatedUser {
                 None => format!("email-{}", row.get::<i64, _>("id")),
             }),
             github_id: row.get::<Option<i64>, _>("github_id").unwrap_or_default(),
-            login: row
-                .get::<Option<String>, _>("email")
-                .unwrap_or_else(|| row.get("login")),
+            // Existing relay versions validate this protocol handle as a GitHub-style
+            // username. The verified email is carried separately for display.
+            login: row.get("login"),
             avatar_url: row.get("avatar_url"),
         },
     }
diff --git a/src/crates/services/miniapp-market-service/src/email_auth.rs b/src/crates/services/miniapp-market-service/src/email_auth.rs
index 2758eb828b..f4ed37137f 100644
--- a/src/crates/services/miniapp-market-service/src/email_auth.rs
+++ b/src/crates/services/miniapp-market-service/src/email_auth.rs
@@ -568,7 +568,13 @@ mod tests {
         assert_eq!(user.profile.github_id, 0);
         assert_eq!(user.email.as_deref(), Some("alice@example.com"));
         assert_eq!(github.email, None);
-        assert_eq!(user.profile.login, "alice@example.com");
+        // Keep the legacy relay profile contract while exposing email separately.
+        assert!(user.profile.login.len() <= 100);
+        assert!(user
+            .profile
+            .login
+            .bytes()
+            .all(|c| c.is_ascii_alphanumeric() || c == b'-'));
         assert!(user.profile.identity_id().unwrap().starts_with("email-"));
         assert!(!service.is_admin(&user));
         let poll = service
@@ -1009,7 +1015,7 @@ mod tests {
             serde_json::from_slice(&to_bytes(response.into_body(), 16384).await.unwrap()).unwrap();
         assert_eq!(profile["email"], "alice@example.com");
         assert!(profile["user"].get("email").is_none());
-        assert_eq!(profile["user"]["login"], "alice@example.com");
+        assert!(!profile["user"]["login"].as_str().unwrap().contains('@'));
     }
 
     #[test]
diff --git a/src/crates/services/skin-market-service/src/auth.rs b/src/crates/services/skin-market-service/src/auth.rs
index 3597090b17..0c8bb2af77 100644
--- a/src/crates/services/skin-market-service/src/auth.rs
+++ b/src/crates/services/skin-market-service/src/auth.rs
@@ -26,6 +26,8 @@ pub(crate) struct AuthenticatedIdentity {
 #[serde(rename_all = "camelCase")]
 struct IdentityResponse {
     user: AppearanceMarketUserSummary,
+    #[serde(default)]
+    email: Option<String>,
     is_admin: bool,
 }
 
@@ -117,9 +119,21 @@ impl IdentityVerifier {
                 "The identity service rejected the verification request.",
             ));
         }
-        let identity: IdentityResponse = response.json().await.map_err(|_| {
+        let mut identity: IdentityResponse = response.json().await.map_err(|_| {
             SkinMarketError::unavailable("The identity service returned an invalid response.")
         })?;
+        // Preserve the authority's protocol handle for older relays; only this
+        // marketplace's public author projection uses the verified email.
+        if identity.user.github_id == 0 {
+            if let Some(email) = identity.email.filter(|email| !email.is_empty()) {
+                if email.len() > 254 || email.chars().any(char::is_control) {
+                    return Err(SkinMarketError::unavailable(
+                        "The identity service returned an invalid email.",
+                    ));
+                }
+                identity.user.login = email;
+            }
+        }
         if identity.user.identity_id().is_none()
             || identity.user.login.trim().is_empty()
             || identity.user.login.len() > 254
diff --git a/src/crates/services/skin-market-service/src/lib.rs b/src/crates/services/skin-market-service/src/lib.rs
index a5a3534ff6..e8ff1d81c4 100644
--- a/src/crates/services/skin-market-service/src/lib.rs
+++ b/src/crates/services/skin-market-service/src/lib.rs
@@ -148,7 +148,7 @@ mod tests {
             .unwrap_or_default();
         let (github_id, login, is_admin) = match token {
             "Bearer owner-token" => (41, "owner", false),
-            "Bearer email-token" => (0, "author@example.com", false),
+            "Bearer email-token" => (0, "user-legacy-handle", false),
             "Bearer admin-token" => (42, "admin", true),
             _ => {
                 return (
@@ -166,6 +166,7 @@ mod tests {
                     "login": login,
                     "avatarUrl": "https://example.invalid/avatar"
                 },
+                "email": if github_id == 0 { Some("author@example.com") } else { None },
                 "isAdmin": is_admin
             })),
         )