少し変更した

.env.example

@@ -45,6 +45,8 @@ MAIL_HOST=smtp.mailtrap.io
 MAIL_PORT=2525
 MAIL_USERNAME=null
 MAIL_PASSWORD=null
+MAIL_NOREPLY_USER=null
+MAIL_NOREPLY_PASS=null
 MAIL_ENCRYPTION=null
 MAIL_OWNER_ADDRESS=null
 MAIL_OWNER_NAME="${APP_NAME}"

app/Http/Controllers/Home/Contact.php

@@ -87,7 +87,7 @@ class Contact {
     // 文章
     if (!isset($this->field['bunsyo']) || is_null($this->field['bunsyo']) || $this->field['bunsyo'] == '') $err[] = '文章をご入力下さい。';
     if (str_contains($this->field['bunsyo'], 'http://') || str_contains($this->field['bunsyo'], 'https://')) $err[] = '文章でURLを入らないで下さい。';
-    $this->field['bunsyo'] = $gpg->encrypt(trim($this->field['bunsyo']));
+    $this->field['bunsyo'] = $gpg->encrypt(trim("メール： ".$this->field['adr']."\n\n".$this->field['bunsyo']));
 
     // 連絡ルール
     if (!$this->field['ruleapply']) $err[] = 'ルールを同意して下さい。';
@@ -110,7 +110,7 @@ class Contact {
     // メールを送る
     try {
       $mail = new MailerController();
-      if (!$mail->compose($this->field)) {
+      if (!$mail->compose($this->field, true)) {
         Storage::disk('public')->delete($this->field['filename']);
         return view('pages.site.contact', ['field' => $this->field, 'err' => ['送信に失敗しました。数時間後もう一回送信してみて下さい。']]);
       }

app/Http/Controllers/MailerController.php

@@ -13,22 +13,27 @@ use PHPMailer\PHPMailer\Exception;
 class MailerController extends Controller {
   public function __construct() {}
 
-  public function compose ($val) {
+  public function compose ($val, $form=false) {
+    mb_language('japanese');
+    mb_internal_encoding('UTF-8');
+
     $mail = new PHPMailer(true);
 
     try {
-      $mail->SMTPDebug = 1;
+      // $mail->SMTPDebug = 2;
       $mail->isSMTP();
       $mail->Host = config('mail.mailers.smtp.host');
       $mail->Port = config('mail.mailers.smtp.port');
       $mail->SMTPSecure = config('mail.mailers.smtp.encryption');
       $mail->SMTPAuth = true;
-      $mail->From = config('mail.owner.address');
-      $mail->Username = config('mail.mailers.smtp.username');
-      $mail->Password = config('mail.mailers.smtp.password');
+      $mail->From = config('mail.'.($form ? 'owner' : 'from').'.address');
+      $mail->FromName = mb_encode_mimeheader(config('mail.mailers.smtp.'.($form ? 'fromname' : 'noreplyfrom')), 'JIS');
+      $mail->Username = config('mail.mailers.smtp.'.($form ? 'username' : 'noreplyuser'));
+      $mail->Password = config('mail.mailers.smtp.'.($form ? 'password' : 'noreplypass'));
 
-      $mail->AddAddress(config('mail.owner.address'));
-      $mail->addReplyTo(config('mail.owner.address'), config('mail.owner.name'));
+      $mail->AddAddress(config('mail.'.($form ? 'owner' : 'from').'.address'));
+      if ($form) $mail->addReplyTo(config('mail.owner.address'), config('mail.owner.name'));
+      else $mail->addReplyTo($val['adr']);
 
       $mail->SMTPOptions = [
         'ssl' => [
@@ -45,13 +50,15 @@ class MailerController extends Controller {
       }
 
       if (isset($val['gpg'])) {
-        $mail->AddStringAttachment($val['gpg'], $val['gpgname']);
+        $mail->AddStringAttachment($val['gpg'], $val['filename']);
+        $mail->AddStringAttachment($val['bunsyo'], $val['adr'].'.gpg');
       }
 
       $mail->isHTML(false);
 
-      $mail->Subject = '【'.$val['catname'].'】'.$val['kenmei'];
-      $mail->Body = "メール：".$val['adr']."\n\n".$val['bunsyo'];
+      $mail->Subject = mb_encode_mimeheader('【'.$val['catname'].'】'.$val['kenmei'], 'JIS');
+      if ($form) $mail->Body = mb_convert_encoding($val['bunsyo'], 'UTF-8');
+      else $mail->Body = mb_convert_encoding($val['bunsyo'], 'JIS');
 
       if (!$mail->send()) {
         Log::critical('Mailer error: ' . $mail->ErrorInfo);

config/mail.php

@@ -39,8 +39,12 @@ return [
       'host' => env('MAIL_HOST', 'smtp.mailgun.org'),
       'port' => env('MAIL_PORT', 587),
       'encryption' => env('MAIL_ENCRYPTION', 'tls'),
+      'fromname' => env('MAIL_OWNER_NAME'),
       'username' => env('MAIL_USERNAME'),
       'password' => env('MAIL_PASSWORD'),
+      'noreplyfrom' => env('MAIL_FROM_NAME'),
+      'noreplyuser' => env('MAIL_NOREPLY_USER'),
+      'noreplypass' => env('MAIL_NOREPLY_PASS'),
       'sendmail' => '/usr/sbin/sendmail -bs',
       'timeout' => null,
       'auth_mode' => null,