diff --git a/database/migrations/2026_07_28_100000_seed_mailboxes_from_environment.php b/database/migrations/2026_07_28_100000_seed_mailboxes_from_environment.php
index efb1d13..420efb0 100644
--- a/database/migrations/2026_07_28_100000_seed_mailboxes_from_environment.php
+++ b/database/migrations/2026_07_28_100000_seed_mailboxes_from_environment.php
@@ -58,6 +58,20 @@ return new class extends Migration
 
     private const UNCONFIGURED_PORT = 2525;
 
+    /**
+     * config/mail.php's own fallback when MAIL_FROM_ADDRESS is unset.
+     *
+     * Same masking problem as UNCONFIGURED_HOST above, and the same fix:
+     * env('MAIL_FROM_ADDRESS', 'hello@example.com') has already substituted
+     * by the time this migration reads config('mail.from.address'), and
+     * 'hello@example.com' is not '', so without this check it would be
+     * seeded as a real From address instead of recognised as "nothing
+     * configured, fall back to the SMTP login". Same trade-off as the host
+     * placeholder too: an install that deliberately wants to send from the
+     * literal address hello@example.com reads as unset — nobody does that.
+     */
+    private const UNCONFIGURED_FROM_ADDRESS = 'hello@example.com';
+
     public function up(): void
     {
         DB::transaction(function () {
@@ -88,10 +102,41 @@ return new class extends Migration
         Settings::set('mail.encryption', $port === 465 ? 'ssl' : 'tls');
 
         $configuredUser = (string) config('mail.mailers.smtp.username', '');
+
+        // Placeholder domain for the four boxes below comes from the SMTP
+        // LOGIN's domain, not from mail.from.address — even though address
+        // itself (below) now prefers mail.from.address for the no-reply box.
+        // The login and the From address can point at different domains (an
+        // API-key login on a shared relay next to a From address on the
+        // install's own domain, or the reverse), and only the login's domain
+        // is proven to accept mail: it is the one .env's MAIL_HOST/
+        // MAIL_USERNAME pair has actually been sending through. Building
+        // support@/billing@/etc. from mail.from.address's domain instead
+        // could seed a placeholder on a domain nobody could ever turn into a
+        // working mailbox.
         $domain = str_contains($configuredUser, '@')
             ? substr($configuredUser, strpos($configuredUser, '@') + 1)
             : 'clupilot.com';
 
+        // The From address actually in force today may not be the SMTP
+        // login — a relay's own account name (an API-key username, a shared
+        // login) is routinely not the address recipients see and can reply
+        // to. A takeover migration's job is to reproduce what the system
+        // already sends, not to improve on it, so address and username are
+        // read and assigned separately rather than collapsing the login into
+        // both.
+        $configuredFromAddress = (string) config('mail.from.address', '');
+        $fromAddress = $configuredFromAddress === self::UNCONFIGURED_FROM_ADDRESS ? '' : $configuredFromAddress;
+
+        // An install with no MAIL_FROM_ADDRESS has nothing better than the
+        // SMTP login to send From — which is what Laravel's own mailer was
+        // already falling back to before this migration, so this reproduces
+        // that install's mail rather than changing it.
+        $resolvedAddress = $fromAddress !== '' ? $fromAddress : $configuredUser;
+
+        $configuredFromName = (string) config('mail.from.name', '');
+        $displayName = $configuredFromName !== '' ? $configuredFromName : 'CluPilot';
+
         // A password may already be stored in the vault. It is CARRIED, not
         // moved: the app_secrets row is deliberately left in place below
         // rather than deleted, so this block only ever reads it.
@@ -111,8 +156,14 @@ return new class extends Migration
 
             $box = Mailbox::firstOrNew(['key' => $key]);
             $box->fill([
-                'address' => $isConfigured ? $configuredUser : $key.'@'.$domain,
-                'display_name' => 'CluPilot',
+                'address' => $isConfigured ? $resolvedAddress : $key.'@'.$domain,
+                'display_name' => $displayName,
+                // Null when the login and address match: Mailbox::
+                // smtpUsername() already falls back to address in that case,
+                // so writing the identical string into both columns would
+                // just be a redundant copy — one more thing to keep in sync
+                // as either changes later through the console.
+                'username' => $isConfigured && $configuredUser !== $resolvedAddress ? $configuredUser : null,
                 'no_reply' => $meta['no_reply'],
                 'active' => true,
             ]);
diff --git a/tests/Feature/Mail/MailboxSeedMigrationTest.php b/tests/Feature/Mail/MailboxSeedMigrationTest.php
index 7fd6b83..e43ced9 100644
--- a/tests/Feature/Mail/MailboxSeedMigrationTest.php
+++ b/tests/Feature/Mail/MailboxSeedMigrationTest.php
@@ -68,6 +68,84 @@ it('still stores a deliberately configured host and port untouched', function ()
         ->and(Settings::get('mail.port'))->toBe(587);
 });
 
+it('seeds address from mail.from.address and keeps the SMTP login as username when they differ', function () {
+    // The installation this reproduces: MAIL_USERNAME is a relay login,
+    // MAIL_FROM_ADDRESS is the address actually in force today. Before this
+    // fix the login was seeded as the From address and username was left
+    // null — invalid mail, or mail sent from the relay login instead of the
+    // sender the system was actually configured to use.
+    clearMailboxSeed();
+    config()->set('mail.mailers.smtp.username', 'no-reply@clupilot.com');
+    config()->set('mail.from.address', 'hello@clupilot.local');
+
+    loadMailboxSeedMigration()->up();
+
+    $box = Mailbox::findByKey('no-reply');
+
+    expect($box->address)->toBe('hello@clupilot.local')
+        ->and($box->username)->toBe('no-reply@clupilot.com');
+});
+
+it('leaves username null when the SMTP login and the From address are the same', function () {
+    // Mailbox::smtpUsername() already falls back to address when username is
+    // null — writing the identical string into both columns is a redundant
+    // copy that only has to drift once (an operator changes one in the
+    // console but not the other) to become a real, harder-to-spot bug.
+    clearMailboxSeed();
+    config()->set('mail.mailers.smtp.username', 'ops@clupilot.com');
+    config()->set('mail.from.address', 'ops@clupilot.com');
+
+    loadMailboxSeedMigration()->up();
+
+    $box = Mailbox::findByKey('no-reply');
+
+    expect($box->address)->toBe('ops@clupilot.com')
+        ->and($box->username)->toBeNull();
+});
+
+it('falls back to the SMTP login for address when MAIL_FROM_ADDRESS was never set', function () {
+    // config/mail.php's own env('MAIL_FROM_ADDRESS', 'hello@example.com') has
+    // already substituted by the time this migration reads config() — an
+    // install that never set MAIL_FROM_ADDRESS reads back that placeholder,
+    // not null, so it has to be recognised the same way UNCONFIGURED_HOST is.
+    clearMailboxSeed();
+    config()->set('mail.mailers.smtp.username', 'no-reply@clupilot.com');
+    config()->set('mail.from.address', 'hello@example.com');
+
+    loadMailboxSeedMigration()->up();
+
+    $box = Mailbox::findByKey('no-reply');
+
+    expect($box->address)->toBe('no-reply@clupilot.com')
+        ->and($box->username)->toBeNull();
+});
+
+it('seeds display_name from mail.from.name instead of a hardcoded CluPilot', function () {
+    clearMailboxSeed();
+    config()->set('mail.mailers.smtp.username', 'no-reply@clupilot.com');
+    config()->set('mail.from.name', 'Example Org Support');
+
+    loadMailboxSeedMigration()->up();
+
+    expect(Mailbox::findByKey('no-reply')->display_name)->toBe('Example Org Support')
+        ->and(Mailbox::findByKey('support')->display_name)->toBe('Example Org Support');
+});
+
+it('still derives the placeholder domain from the SMTP login, not from mail.from.address', function () {
+    // The two can point at different domains. Only the login's domain is
+    // proven to accept mail for this install — switching the placeholder
+    // domain to mail.from.address's domain could seed support@/billing@/etc.
+    // on a domain nobody could ever turn into a working mailbox.
+    clearMailboxSeed();
+    config()->set('mail.mailers.smtp.username', 'no-reply@clupilot.com');
+    config()->set('mail.from.address', 'hello@clupilot.local');
+
+    loadMailboxSeedMigration()->up();
+
+    expect(Mailbox::findByKey('support')->address)->toBe('support@clupilot.com')
+        ->and(Mailbox::findByKey('billing')->address)->toBe('billing@clupilot.com');
+});
+
 it('carries the vault password across as ciphertext, never decrypting and re-encrypting it', function () {
     clearMailboxSeed();
     config()->set('mail.mailers.smtp.username', 'no-reply@clupilot.com');