diff --git a/scripts/android-browser-staging-e2e.sh b/scripts/android-browser-staging-e2e.sh
index 6e146d8..e66e667 100755
--- a/scripts/android-browser-staging-e2e.sh
+++ b/scripts/android-browser-staging-e2e.sh
@@ -58,6 +58,14 @@ fi
 : "${WNH_BASE_URL:?WNH_BASE_URL is missing from .env}"
 : "${WNH_TRACKING_MIN_TIME_MS:?WNH_TRACKING_MIN_TIME_MS is missing from .env}"
 : "${WNH_TRACKING_HTTP_TIMEOUT_MS:?WNH_TRACKING_HTTP_TIMEOUT_MS is missing from .env}"
+: "${MAILPIT_BIND_ADDRESS:?MAILPIT_BIND_ADDRESS is missing from .env}"
+: "${MAILPIT_PORT:?MAILPIT_PORT is missing from .env}"
+
+if [[ ! "$MAILPIT_PORT" =~ ^[0-9]+$ ]] ||
+  ((MAILPIT_PORT < 1 || MAILPIT_PORT > 65535)); then
+  echo "MAILPIT_PORT must be between 1 and 65535." >&2
+  exit 1
+fi
 
 case "$WNH_BASE_URL" in
   https://*/* | https://*) ;;
@@ -75,6 +83,12 @@ case "$origin_without_scheme" in
     ;;
 esac
 expected_host=${origin_without_scheme%%:*}
+mailpit_host=$MAILPIT_BIND_ADDRESS
+case "$mailpit_host" in
+  0.0.0.0 | ::) mailpit_host=127.0.0.1 ;;
+  *:*) mailpit_host="[$mailpit_host]" ;;
+esac
+mailpit_url="http://${mailpit_host}:${MAILPIT_PORT}"
 
 mkdir -p "$output_dir"
 chmod 700 "$ROOT/output" "$ROOT/output/android-browser-staging-e2e" "$output_dir"
@@ -161,7 +175,7 @@ run_browser_phase() {
     --network host \
     --user "$(id -u):$(id -g)" \
     --env "BASE_URL=$WNH_BASE_URL" \
-    --env MAILPIT_URL=http://127.0.0.1:8027 \
+    --env "MAILPIT_URL=$mailpit_url" \
     --env "CROSS_CLIENT_PHASE=$phase" \
     --env "CROSS_CLIENT_REQUESTER_EMAIL=$requester_email" \
     --env "CROSS_CLIENT_PASSWORD=$fixture_password" \
diff --git a/scripts/staging-e2e-run.sh b/scripts/staging-e2e-run.sh
index df6e31b..96eec80 100755
--- a/scripts/staging-e2e-run.sh
+++ b/scripts/staging-e2e-run.sh
@@ -26,6 +26,14 @@ fi
 : "${PHX_HOST:?PHX_HOST is missing from .env}"
 : "${PHX_SCHEME:?PHX_SCHEME is missing from .env}"
 : "${PHX_URL_PORT:?PHX_URL_PORT is missing from .env}"
+: "${MAILPIT_BIND_ADDRESS:?MAILPIT_BIND_ADDRESS is missing from .env}"
+: "${MAILPIT_PORT:?MAILPIT_PORT is missing from .env}"
+
+if [[ ! "$MAILPIT_PORT" =~ ^[0-9]+$ ]] ||
+  ((MAILPIT_PORT < 1 || MAILPIT_PORT > 65535)); then
+  echo "MAILPIT_PORT must be between 1 and 65535." >&2
+  exit 1
+fi
 
 if [[ "$PHX_SCHEME" != https ]]; then
   echo "Public staging E2E requires PHX_SCHEME=https." >&2
@@ -35,6 +43,12 @@ fi
 run_id="$(date -u +%Y%m%d%H%M%S)-$$"
 output_dir="$ROOT/output/staging-e2e/$run_id"
 base_url="${PHX_SCHEME}://${PHX_HOST}"
+mailpit_host=$MAILPIT_BIND_ADDRESS
+case "$mailpit_host" in
+  0.0.0.0 | ::) mailpit_host=127.0.0.1 ;;
+  *:*) mailpit_host="[$mailpit_host]" ;;
+esac
+mailpit_url="http://${mailpit_host}:${MAILPIT_PORT}"
 
 if [[ "$PHX_URL_PORT" != 443 ]]; then
   base_url="${base_url}:${PHX_URL_PORT}"
@@ -152,7 +166,7 @@ docker run --rm \
   --network host \
   --user "$(id -u):$(id -g)" \
   --env "BASE_URL=$base_url" \
-  --env MAILPIT_URL=http://127.0.0.1:8027 \
+  --env "MAILPIT_URL=$mailpit_url" \
   --env "E2E_RUN_ID=$run_id" \
   --env "E2E_FIXTURE_PASSWORD=$fixture_password" \
   --env HOME=/tmp \
diff --git a/scripts/staging-full-e2e-run.sh b/scripts/staging-full-e2e-run.sh
index 7c51481..57e02d4 100755
--- a/scripts/staging-full-e2e-run.sh
+++ b/scripts/staging-full-e2e-run.sh
@@ -30,6 +30,14 @@ fi
 : "${PHX_HOST:?PHX_HOST is missing from .env}"
 : "${PHX_SCHEME:?PHX_SCHEME is missing from .env}"
 : "${PHX_URL_PORT:?PHX_URL_PORT is missing from .env}"
+: "${MAILPIT_BIND_ADDRESS:?MAILPIT_BIND_ADDRESS is missing from .env}"
+: "${MAILPIT_PORT:?MAILPIT_PORT is missing from .env}"
+
+if [[ ! "$MAILPIT_PORT" =~ ^[0-9]+$ ]] ||
+  ((MAILPIT_PORT < 1 || MAILPIT_PORT > 65535)); then
+  echo "MAILPIT_PORT must be between 1 and 65535." >&2
+  exit 1
+fi
 
 if [[ "$PHX_SCHEME" != https ]]; then
   echo "Public staging E2E requires PHX_SCHEME=https." >&2
@@ -39,7 +47,12 @@ fi
 run_id="$(date -u +%Y%m%d%H%M%S)-$$"
 output_dir="$ROOT/output/staging-full-e2e/$run_id"
 base_url="${PHX_SCHEME}://${PHX_HOST}"
-mailpit_url=http://127.0.0.1:8027
+mailpit_host=$MAILPIT_BIND_ADDRESS
+case "$mailpit_host" in
+  0.0.0.0 | ::) mailpit_host=127.0.0.1 ;;
+  *:*) mailpit_host="[$mailpit_host]" ;;
+esac
+mailpit_url="http://${mailpit_host}:${MAILPIT_PORT}"
 admin_email="wnh-staging-e2e-$run_id-admin@example.invalid"
 
 if [[ "$PHX_URL_PORT" != 443 ]]; then