diff --git a/CHANGELOG.md b/CHANGELOG.md
index 09304fd..e625d1a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,18 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog](https://keepachangelog.com/), and this project adheres to [Semantic Versioning](https://semver.org/).
 
+## [2.8.1] - 2026-09-20
+
+### Fixed
+
+- **`getScheduled()` threw for a legacy transmission id.** An id handed out before Lettr held scheduled emails itself is answered from delivery events, in a shape that has no `sch_` id, and 2.8.0 required one — so it threw `InvalidValueException: Request ID cannot be empty.` `requestId` now falls back to the transmission id in that response, so it is always the id that addresses the email you asked about.
+
+  2.8.0 fixed reading back `sch_` ids and broke this path in the same change. Only that one path is affected; everything else in 2.8.0 is unchanged.
+
+- **`getScheduled()` threw for a legacy transmission id a second way.** The same response reports the *provider's* states, not Lettr's — a delivered email reads back `delivered`, which is not one of the five `ScheduledEmailState` cases, so `ScheduledEmailState::from()` threw `ValueError`. Confirmed against the live API, which answers `state: "delivered"` for an id with delivery events.
+
+  `ScheduledEmailState` now also carries `Submitted`, `Generating`, `Delivered` and `Bounced`, marked deprecated because only that legacy path can produce them, plus `Unknown`. An unrecognised value resolves to `Unknown` rather than throwing, so a state the API adds later cannot break reads again.
+
 ## [2.8.0] - 2026-09-20
 
 Scheduled emails changed shape on the API side, and this release catches the SDK up. **If you schedule emails, `getScheduled()` currently throws against the live API — upgrade.** Nothing outside scheduled emails is touched: `send()`, `find()`, `list()`, templates, audience and campaigns are all unchanged, as are `TransmissionDetail` and `TransmissionState`.
diff --git a/src/Dto/Email/ScheduledEmail.php b/src/Dto/Email/ScheduledEmail.php
index 90e4578..82f49e4 100644
--- a/src/Dto/Email/ScheduledEmail.php
+++ b/src/Dto/Email/ScheduledEmail.php
@@ -16,7 +16,10 @@
  * Two ids, and they are not interchangeable:
  *
  * - `requestId` (`sch_...`) identifies the scheduled email for its whole life
- *   and is what `getScheduled()` and `cancelScheduled()` take.
+ *   and is what `getScheduled()` and `cancelScheduled()` take. Reading back a
+ *   legacy provider transmission id answers from delivery events, and this
+ *   then carries that transmission id - so it is always the id that addresses
+ *   the email you asked about.
  * - `transmissionId` is the sending provider's id. It is `null` until the
  *   email is actually sent, and it is the value that appears on webhook
  *   events, so use it to correlate them.
@@ -57,10 +60,16 @@ public static function from(array $data): self
         /** @var array<string> $recipients */
         $recipients = $data['recipients'] ?? [];
 
+        // Reading back a legacy provider transmission id - one handed out
+        // before Lettr held scheduled emails itself - is answered from
+        // delivery events, in a shape that has no `sch_` id. The id the caller
+        // addressed it with is the transmission id, so fall back to that.
+        $requestId = (string) ($data['request_id'] ?? $data['transmission_id'] ?? '');
+
         return new self(
-            requestId: new RequestId((string) $data['request_id']),
+            requestId: new RequestId($requestId),
             transmissionId: isset($data['transmission_id']) ? (string) $data['transmission_id'] : null,
-            state: ScheduledEmailState::from((string) $data['state']),
+            state: ScheduledEmailState::fromWire((string) $data['state']),
             scheduledAt: (string) $data['scheduled_at'],
             from: (string) $data['from'],
             fromName: isset($data['from_name']) ? (string) $data['from_name'] : null,
diff --git a/src/Enums/ScheduledEmailState.php b/src/Enums/ScheduledEmailState.php
index 162d3ba..dcb303b 100644
--- a/src/Enums/ScheduledEmailState.php
+++ b/src/Enums/ScheduledEmailState.php
@@ -29,6 +29,39 @@ enum ScheduledEmailState: string
     /** Sending was attempted and gave up. See `failureReason`. */
     case Failed = 'failed';
 
+    /*
+     * The states below are the sending provider's, not Lettr's. Reading back a
+     * legacy provider transmission id is answered from delivery events, which
+     * report the provider's vocabulary - so these arrive on that path only, and
+     * never on a `sch_` id.
+     */
+
+    /** @deprecated Legacy provider state. */
+    case Submitted = 'submitted';
+
+    /** @deprecated Legacy provider state. */
+    case Generating = 'generating';
+
+    /** @deprecated Legacy provider state. */
+    case Delivered = 'delivered';
+
+    /** @deprecated Legacy provider state. */
+    case Bounced = 'bounced';
+
+    /** A state this version of the SDK does not know. */
+    case Unknown = 'unknown';
+
+    /**
+     * Resolve a wire value, without throwing on one we do not know.
+     *
+     * A state the API adds later must not turn every read into a `ValueError`,
+     * so an unrecognised value becomes {@see self::Unknown}.
+     */
+    public static function fromWire(string $value): self
+    {
+        return self::tryFrom($value) ?? self::Unknown;
+    }
+
     /** Whether the email can still be cancelled. */
     public function isCancellable(): bool
     {
@@ -39,8 +72,10 @@ public function isCancellable(): bool
     public function isTerminal(): bool
     {
         return match ($this) {
-            self::Sent, self::Cancelled, self::Failed => true,
-            self::Scheduled, self::Sending => false,
+            self::Sent, self::Cancelled, self::Failed,
+            self::Delivered, self::Bounced => true,
+            self::Scheduled, self::Sending,
+            self::Submitted, self::Generating, self::Unknown => false,
         };
     }
 }
diff --git a/src/Lettr.php b/src/Lettr.php
index 37d3c6b..ef55e30 100644
--- a/src/Lettr.php
+++ b/src/Lettr.php
@@ -39,7 +39,7 @@ final class Lettr
      *             single source of truth for the version and will be removed in
      *             a future major release.
      */
-    public const VERSION = '2.8.0';
+    public const VERSION = '2.8.1';
 
     /**
      * The API base URL.
diff --git a/tests/Unit/LettrTest.php b/tests/Unit/LettrTest.php
index 8ca9c43..5740a97 100644
--- a/tests/Unit/LettrTest.php
+++ b/tests/Unit/LettrTest.php
@@ -193,7 +193,7 @@
 })->throws(InvalidArgumentException::class, 'Unknown service: unknownService');
 
 test('has correct version constant', function (): void {
-    expect(Lettr::VERSION)->toBe('2.8.0');
+    expect(Lettr::VERSION)->toBe('2.8.1');
 });
 
 test('has correct base url constant', function (): void {
diff --git a/tests/Unit/Services/EmailServiceTest.php b/tests/Unit/Services/EmailServiceTest.php
index a977ea3..553c477 100644
--- a/tests/Unit/Services/EmailServiceTest.php
+++ b/tests/Unit/Services/EmailServiceTest.php
@@ -614,3 +614,53 @@
         'GET emails/scheduled/sch_01JQZ3N2K8XW9V6M4TBRC7YHDE',
     ])->and($cancelled->state)->toBe(ScheduledEmailState::Cancelled);
 });
+
+test('getScheduled still reads back a legacy transmission id', function (): void {
+    // Ids handed out before Lettr held scheduled emails itself are answered
+    // from delivery events, in the older shape: no request_id, no
+    // accepted/rejected/tag, and the provider's own states.
+    $transporter = new MockTransporter;
+    $transporter->response = [
+        'transmission_id' => '7686140844331501179',
+        // A state only that path reports. Lettr never says 'delivered' about a
+        // scheduled email - once it is sent, delivery lives on the events.
+        'state' => 'delivered',
+        'scheduled_at' => '2026-09-16T15:00:00+00:00',
+        'from' => 'sender@example.com',
+        'from_name' => 'Sender Name',
+        'subject' => 'Scheduled Newsletter',
+        'recipients' => ['r@example.com'],
+        'num_recipients' => 1,
+        'events' => [],
+    ];
+
+    $scheduled = (new EmailService($transporter))->getScheduled('7686140844331501179');
+
+    expect($scheduled->transmissionId)->toBe('7686140844331501179')
+        // No sch_ id in this shape, so it falls back to the id used to ask.
+        ->and((string) $scheduled->requestId)->toBe('7686140844331501179')
+        ->and($scheduled->state)->toBe(ScheduledEmailState::Delivered)
+        ->and($scheduled->accepted)->toBe(0)
+        ->and($scheduled->tag)->toBeNull();
+});
+
+test('an unrecognised state reads back as Unknown rather than throwing', function (): void {
+    // A state the API adds after this version ships must not turn every read
+    // into a ValueError.
+    $transporter = new MockTransporter;
+    $transporter->response = [
+        'request_id' => 'sch_01JQZ3N2K8XW9V6M4TBRC7YHDE',
+        'transmission_id' => null,
+        'state' => 'a_state_from_the_future',
+        'scheduled_at' => '2026-09-16T15:00:00+00:00',
+        'from' => 'sender@example.com',
+        'recipients' => ['r@example.com'],
+        'num_recipients' => 1,
+        'events' => [],
+    ];
+
+    $scheduled = (new EmailService($transporter))->getScheduled('sch_01JQZ3N2K8XW9V6M4TBRC7YHDE');
+
+    expect($scheduled->state)->toBe(ScheduledEmailState::Unknown)
+        ->and($scheduled->state->isCancellable())->toBeFalse();
+});