diff --git a/deploy.sh b/deploy.sh
index c6c6f3d..8a534ad 100755
--- a/deploy.sh
+++ b/deploy.sh
@@ -38,6 +38,7 @@ CFG_PUBLIC_API_BASE_URL="/api/v1"
 CFG_ADMIN_CREATE="no"; CFG_ADMIN_USER=""; CFG_ADMIN_PASS=""
 CFG_ML_URL=""
 CFG_ACOUSTID_KEY=""
+CFG_MUSICBRAINZ_OWNER_EMAIL=""
 CFG_JWT_SECRET=""
 
 # ==========================================================================
@@ -190,6 +191,8 @@ step_enrichment() {
     ui_title "$(t step_enrichment)"
     ui_dim "$(t enrichment_note)"
     ui_input "$(t acoustid_prompt)" "" ""; CFG_ACOUSTID_KEY="$UI_VALUE"
+    ui_dim "$(t musicbrainz_note)"
+    ui_input "$(t musicbrainz_email_prompt)" "" v_email_opt; CFG_MUSICBRAINZ_OWNER_EMAIL="$UI_VALUE"
 }
 
 access_url() {
diff --git a/i18n/en.sh b/i18n/en.sh
index 5e5568c..b21b34e 100644
--- a/i18n/en.sh
+++ b/i18n/en.sh
@@ -103,6 +103,8 @@ MSG[ml_prompt]="ML service URL (leave blank — backend degrades gracefully)"
 MSG[step_enrichment]="Metadata enrichment (optional)"
 MSG[enrichment_note]="Imported files are auto-tagged from their embedded tags. Add an AcoustID key to also identify untagged files by audio fingerprint (free: https://acoustid.org/new-application)."
 MSG[acoustid_prompt]="AcoustID API key (leave blank to use embedded tags only)"
+MSG[musicbrainz_note]="MusicBrainz/AcoustID require a contact email in their User-Agent or they may throttle requests."
+MSG[musicbrainz_email_prompt]="Contact email for MusicBrainz/AcoustID (leave blank to use the project's default)"
 
 # -- summary / run ---------------------------------------------------------
 MSG[summary_title]="Summary (secrets hidden)"
diff --git a/i18n/ru.sh b/i18n/ru.sh
index 348be57..3a1fb0e 100644
--- a/i18n/ru.sh
+++ b/i18n/ru.sh
@@ -103,6 +103,8 @@ MSG[ml_prompt]="URL ML-сервиса (оставьте пустым — backend
 MSG[step_enrichment]="Обогащение метаданных (опционально)"
 MSG[enrichment_note]="Импортируемые файлы тегируются из встроенных тегов. Добавьте ключ AcoustID, чтобы опознавать файлы без тегов по аудио-отпечатку (бесплатно: https://acoustid.org/new-application)."
 MSG[acoustid_prompt]="API-ключ AcoustID (пусто — только встроенные теги)"
+MSG[musicbrainz_note]="MusicBrainz/AcoustID требуют контактный email в User-Agent, иначе запросы могут ограничиваться (throttling)."
+MSG[musicbrainz_email_prompt]="Контактный email для MusicBrainz/AcoustID (пусто — использовать значение по умолчанию)"
 
 # -- summary / run ---------------------------------------------------------
 MSG[summary_title]="Сводка (секреты скрыты)"
diff --git a/lib/env_gen.sh b/lib/env_gen.sh
index 08ea16f..a620ed1 100644
--- a/lib/env_gen.sh
+++ b/lib/env_gen.sh
@@ -84,5 +84,14 @@ generate_env() {
         } >>"$ENV_FILE"
     fi
 
+    # -- MusicBrainz/AcoustID contact (required by their usage policy) ----
+    if [[ -n "${CFG_MUSICBRAINZ_OWNER_EMAIL:-}" ]]; then
+        {
+            echo ""
+            echo "# -- MusicBrainz/AcoustID contact ----------------------------------------"
+            echo "MUSICBRAINZ_OWNER_EMAIL=${CFG_MUSICBRAINZ_OWNER_EMAIL}"
+        } >>"$ENV_FILE"
+    fi
+
     chmod 600 "$ENV_FILE"
 }
diff --git a/lib/ui.sh b/lib/ui.sh
index ff760aa..62a390f 100644
--- a/lib/ui.sh
+++ b/lib/ui.sh
@@ -132,3 +132,4 @@ v_port()     { [[ "$1" =~ ^[0-9]+$ ]] && (($1 >= 1 && $1 <= 65535)) || { ui_warn
 v_url()      { [[ "$1" =~ ^https?:// ]] || { ui_warn "$(t invalid_input)"; return 1; }; }
 v_redis()    { [[ "$1" =~ ^rediss?:// ]] || { ui_warn "$(t invalid_input)"; return 1; }; }
 v_domain()   { [[ "$1" =~ ^[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$ ]] || { ui_warn "$(t invalid_input)"; return 1; }; }
+v_email_opt() { [[ -z "$1" || "$1" =~ ^[^[:space:]@]+@[^[:space:]@]+\.[a-zA-Z]{2,}$ ]] || { ui_warn "$(t invalid_input)"; return 1; }; }
diff --git a/templates/env/env.template b/templates/env/env.template
index e5df296..74f3959 100644
--- a/templates/env/env.template
+++ b/templates/env/env.template
@@ -33,7 +33,6 @@ STORAGE_BACKEND=@STORAGE_BACKEND@
 # Browser-facing API base URL. Injected into the webui at container start
 # (window.__APP_CONFIG__). '/api/v1' = same-origin behind the reverse proxy.
 PUBLIC_API_BASE_URL=@PUBLIC_API_BASE_URL@
-MUSICBRAINZ_USER_AGENT=mcma-backend/0.1.0 ( https://github.com/your/repo )
 
 # -- published ports ------------------------------------------------------
 HTTP_PORT=@HTTP_PORT@