From 1559f250844709a8d0265802f078a572485eec23 Mon Sep 17 00:00:00 2001
From: Simon Leary <simon.leary42@proton.me>
Date: Fri, 3 Apr 2026 09:38:48 -0400
Subject: [PATCH 1/6] enable exceptions

---
 resources/lib/UnityMailer.php | 9 ++-------
 1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/resources/lib/UnityMailer.php b/resources/lib/UnityMailer.php
index 73f59e32e..19fda6718 100644
--- a/resources/lib/UnityMailer.php
+++ b/resources/lib/UnityMailer.php
@@ -6,8 +6,6 @@
 use Exception;
 use Twig\TwigFunction;
 
-class UnityMailerException extends Exception {}
-
 /**
  * This is a class that uses PHPmailer to send emails based on templates
  */
@@ -27,7 +25,7 @@ class UnityMailer extends PHPMailer
 
     public function __construct()
     {
-        parent::__construct();
+        parent::__construct(exceptions: true);
         $this->isSMTP();
 
         $this->MSG_SENDER_EMAIL = CONFIG["mail"]["sender"];
@@ -122,10 +120,7 @@ public function sendMail(string|array $recipients, string $template, ?array $dat
             }
         }
 
-        $output = parent::send();
-        if ($output === false) {
-            throw new UnityMailerException($this->ErrorInfo);
-        }
+        parent::send();
         $this->clearAllRecipients();
     }
 }

From 5455b77611fed8f0c05d05ea9cc29cc872fd0dfe Mon Sep 17 00:00:00 2001
From: Simon Leary <simon.leary42@proton.me>
Date: Fri, 3 Apr 2026 09:47:52 -0400
Subject: [PATCH 2/6] reset state after message send

---
 resources/lib/UnityMailer.php | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

diff --git a/resources/lib/UnityMailer.php b/resources/lib/UnityMailer.php
index 19fda6718..0f1e94131 100644
--- a/resources/lib/UnityMailer.php
+++ b/resources/lib/UnityMailer.php
@@ -93,6 +93,26 @@ public function __construct()
         $this->twig->addGlobal("CONFIG", CONFIG);
     }
 
+    private function resetMessageState(): void
+    {
+        $this->clearAllRecipients();
+        $this->clearAttachments();
+        $this->clearCustomHeaders();
+        $this->CharSet = self::CHARSET_ISO88591;
+        $this->ContentType = self::CONTENT_TYPE_PLAINTEXT;
+        $this->Encoding = self::ENCODING_8BIT;
+        $this->From = "";
+        $this->FromName = "";
+        $this->Sender = "";
+        $this->Subject = "";
+        $this->Body = "";
+        $this->AltBody = "";
+        $this->Ical = "";
+        $this->ConfirmReadingTo = "";
+        $this->MessageID = "";
+        $this->MessageDate = "";
+    }
+
     /**
      * @param string|string[] $recipients
      * @param ?mixed[] $data
@@ -119,8 +139,10 @@ public function sendMail(string|array $recipients, string $template, ?array $dat
                 $this->addAddress($recipients);
             }
         }
-
-        parent::send();
-        $this->clearAllRecipients();
+        try {
+            parent::send();
+        } finally {
+            $this->resetMessageState();
+        }
     }
 }

From ade52d54a11485812d5650e8fb85beac43f4dd58 Mon Sep 17 00:00:00 2001
From: Simon Leary <simon.leary42@proton.me>
Date: Fri, 3 Apr 2026 11:26:50 -0400
Subject: [PATCH 3/6] construct a new PHPMailer object for each message

---
 resources/lib/UnityMailer.php | 101 ++++++++++++++--------------------
 1 file changed, 41 insertions(+), 60 deletions(-)

diff --git a/resources/lib/UnityMailer.php b/resources/lib/UnityMailer.php
index 0f1e94131..6758fd770 100644
--- a/resources/lib/UnityMailer.php
+++ b/resources/lib/UnityMailer.php
@@ -9,7 +9,7 @@
 /**
  * This is a class that uses PHPmailer to send emails based on templates
  */
-class UnityMailer extends PHPMailer
+class UnityMailer
 {
     private string $MSG_SENDER_EMAIL;
     private string $MSG_SENDER_NAME;
@@ -25,9 +25,6 @@ class UnityMailer extends PHPMailer
 
     public function __construct()
     {
-        parent::__construct(exceptions: true);
-        $this->isSMTP();
-
         $this->MSG_SENDER_EMAIL = CONFIG["mail"]["sender"];
         $this->MSG_SENDER_NAME = CONFIG["mail"]["sender_name"];
         $this->MSG_SUPPORT_EMAIL = CONFIG["mail"]["support"];
@@ -36,15 +33,37 @@ public function __construct()
         $this->MSG_ADMIN_NAME = CONFIG["mail"]["admin_name"];
         $this->MSG_PI_APPROVAL_EMAIL = CONFIG["mail"]["pi_approve"];
         $this->MSG_PI_APPROVAL_NAME = CONFIG["mail"]["pi_approve_name"];
+        $this->loader = new \Twig\Loader\FilesystemLoader([
+            __DIR__ . "/../../deployment/mail_overrides",
+            __DIR__ . "/../mail",
+        ]);
+        $this->twig = new \Twig\Environment($this->loader, ["strict_variables" => true]);
+        $functions = [
+            new TwigFunction("setSubject", fn($x) => ($this->Subject = $x)),
+            new TwigFunction("getRelativeHyperlink", getRelativeHyperlink(...)),
+            new TwigFunction("formatHyperlink", formatHyperlink(...)),
+            new TwigFunction("throw", fn($x) => throw new Exception($x)),
+        ];
+        foreach ($functions as $function) {
+            $this->twig->addFunction($function);
+        }
+        $this->twig->addGlobal("CONFIG", CONFIG);
+    }
+
+    public function constructPHPMailer(): PHPMailer
+    {
+        $mailer = new PHPMailer(exceptions: true);
+        $mailer->isSMTP();
+
         if (empty(CONFIG["smtp"]["host"])) {
             throw new Exception("SMTP server hostname not set");
         }
-        $this->Host = CONFIG["smtp"]["host"];
+        $mailer->Host = CONFIG["smtp"]["host"];
 
         if (empty(CONFIG["smtp"]["port"])) {
             throw new Exception("SMTP server port not set");
         }
-        $this->Port = CONFIG["smtp"]["port"];
+        $mailer->Port = CONFIG["smtp"]["port"];
 
         $security = CONFIG["smtp"]["security"];
         $security_conf_valid = empty($security) || $security == "tls" || $security == "ssl";
@@ -53,21 +72,21 @@ public function __construct()
                 "SMTP security is not set correctly, leave empty, use 'tls', or 'ssl'",
             );
         }
-        $this->SMTPSecure = $security;
+        $mailer->SMTPSecure = $security;
 
         if (!empty(CONFIG["smtp"]["user"])) {
-            $this->SMTPAuth = true;
-            $this->Username = CONFIG["smtp"]["user"];
+            $mailer->SMTPAuth = true;
+            $mailer->Username = CONFIG["smtp"]["user"];
         } else {
-            $this->SMTPAuth = false;
+            $mailer->SMTPAuth = false;
         }
 
         if (!empty(CONFIG["smtp"]["pass"])) {
-            $this->Password = CONFIG["smtp"]["pass"];
+            $mailer->Password = CONFIG["smtp"]["pass"];
         }
 
         if (CONFIG["smtp"]["ssl_verify"] == "false") {
-            $this->SMTPOptions = [
+            $mailer->SMTPOptions = [
                 "ssl" => [
                     "verify_peer" => false,
                     "verify_peer_name" => false,
@@ -75,42 +94,7 @@ public function __construct()
                 ],
             ];
         }
-
-        $this->loader = new \Twig\Loader\FilesystemLoader([
-            __DIR__ . "/../../deployment/mail_overrides",
-            __DIR__ . "/../mail",
-        ]);
-        $this->twig = new \Twig\Environment($this->loader, ["strict_variables" => true]);
-        $functions = [
-            new TwigFunction("setSubject", fn($x) => ($this->Subject = $x)),
-            new TwigFunction("getRelativeHyperlink", getRelativeHyperlink(...)),
-            new TwigFunction("formatHyperlink", formatHyperlink(...)),
-            new TwigFunction("throw", fn($x) => throw new Exception($x)),
-        ];
-        foreach ($functions as $function) {
-            $this->twig->addFunction($function);
-        }
-        $this->twig->addGlobal("CONFIG", CONFIG);
-    }
-
-    private function resetMessageState(): void
-    {
-        $this->clearAllRecipients();
-        $this->clearAttachments();
-        $this->clearCustomHeaders();
-        $this->CharSet = self::CHARSET_ISO88591;
-        $this->ContentType = self::CONTENT_TYPE_PLAINTEXT;
-        $this->Encoding = self::ENCODING_8BIT;
-        $this->From = "";
-        $this->FromName = "";
-        $this->Sender = "";
-        $this->Subject = "";
-        $this->Body = "";
-        $this->AltBody = "";
-        $this->Ical = "";
-        $this->ConfirmReadingTo = "";
-        $this->MessageID = "";
-        $this->MessageDate = "";
+        return $mailer;
     }
 
     /**
@@ -120,29 +104,26 @@ private function resetMessageState(): void
     public function sendMail(string|array $recipients, string $template, ?array $data = null): void
     {
         $data ??= [];
-        $this->setFrom($this->MSG_SENDER_EMAIL, $this->MSG_SENDER_NAME);
-        $this->addReplyTo($this->MSG_SUPPORT_EMAIL, $this->MSG_SUPPORT_NAME);
+        $mailer = $this->constructPHPMailer();
+        $mailer->setFrom($this->MSG_SENDER_EMAIL, $this->MSG_SENDER_NAME);
+        $mailer->addReplyTo($this->MSG_SUPPORT_EMAIL, $this->MSG_SUPPORT_NAME);
 
         $mes_html = $this->twig->render("$template.html.twig", $data);
-        $this->msgHTML($mes_html);
+        $mailer->msgHTML($mes_html);
 
         if ($recipients == "admin") {
-            $this->addBCC($this->MSG_ADMIN_EMAIL, $this->MSG_ADMIN_NAME);
+            $mailer->addBCC($this->MSG_ADMIN_EMAIL, $this->MSG_ADMIN_NAME);
         } elseif ($recipients == "pi_approve") {
-            $this->addBCC($this->MSG_PI_APPROVAL_EMAIL, $this->MSG_PI_APPROVAL_NAME);
+            $mailer->addBCC($this->MSG_PI_APPROVAL_EMAIL, $this->MSG_PI_APPROVAL_NAME);
         } else {
             if (is_array($recipients)) {
                 foreach ($recipients as $addr) {
-                    $this->addBCC($addr);
+                    $mailer->addBCC($addr);
                 }
             } else {
-                $this->addAddress($recipients);
+                $mailer->addAddress($recipients);
             }
         }
-        try {
-            parent::send();
-        } finally {
-            $this->resetMessageState();
-        }
+        $mailer->send();
     }
 }

From d2659aeb43d6c19aa8cf8475045609bae2eb5fb4 Mon Sep 17 00:00:00 2001
From: Simon Leary <simon.leary42@proton.me>
Date: Fri, 3 Apr 2026 13:07:02 -0400
Subject: [PATCH 4/6] create a new twig environment each message

---
 resources/lib/UnityMailer.php | 43 +++++++++++++++++++----------------
 1 file changed, 24 insertions(+), 19 deletions(-)

diff --git a/resources/lib/UnityMailer.php b/resources/lib/UnityMailer.php
index 6758fd770..f0b72bf49 100644
--- a/resources/lib/UnityMailer.php
+++ b/resources/lib/UnityMailer.php
@@ -20,9 +20,6 @@ class UnityMailer
     private string $MSG_PI_APPROVAL_EMAIL;
     private string $MSG_PI_APPROVAL_NAME;
 
-    private \Twig\Loader\FilesystemLoader $loader;
-    private \Twig\Environment $twig;
-
     public function __construct()
     {
         $this->MSG_SENDER_EMAIL = CONFIG["mail"]["sender"];
@@ -33,21 +30,6 @@ public function __construct()
         $this->MSG_ADMIN_NAME = CONFIG["mail"]["admin_name"];
         $this->MSG_PI_APPROVAL_EMAIL = CONFIG["mail"]["pi_approve"];
         $this->MSG_PI_APPROVAL_NAME = CONFIG["mail"]["pi_approve_name"];
-        $this->loader = new \Twig\Loader\FilesystemLoader([
-            __DIR__ . "/../../deployment/mail_overrides",
-            __DIR__ . "/../mail",
-        ]);
-        $this->twig = new \Twig\Environment($this->loader, ["strict_variables" => true]);
-        $functions = [
-            new TwigFunction("setSubject", fn($x) => ($this->Subject = $x)),
-            new TwigFunction("getRelativeHyperlink", getRelativeHyperlink(...)),
-            new TwigFunction("formatHyperlink", formatHyperlink(...)),
-            new TwigFunction("throw", fn($x) => throw new Exception($x)),
-        ];
-        foreach ($functions as $function) {
-            $this->twig->addFunction($function);
-        }
-        $this->twig->addGlobal("CONFIG", CONFIG);
     }
 
     public function constructPHPMailer(): PHPMailer
@@ -97,6 +79,25 @@ public function constructPHPMailer(): PHPMailer
         return $mailer;
     }
 
+    public function constructTwigEnvironment(): \Twig\Environment
+    {
+        $loader = new \Twig\Loader\FilesystemLoader([
+            __DIR__ . "/../../deployment/mail_overrides",
+            __DIR__ . "/../mail",
+        ]);
+        $twig = new \Twig\Environment($loader, ["strict_variables" => true]);
+        $functions = [
+            new TwigFunction("getRelativeHyperlink", getRelativeHyperlink(...)),
+            new TwigFunction("formatHyperlink", formatHyperlink(...)),
+            new TwigFunction("throw", fn($x) => throw new Exception($x)),
+        ];
+        foreach ($functions as $function) {
+            $twig->addFunction($function);
+        }
+        $twig->addGlobal("CONFIG", CONFIG);
+        return $twig;
+    }
+
     /**
      * @param string|string[] $recipients
      * @param ?mixed[] $data
@@ -105,10 +106,14 @@ public function sendMail(string|array $recipients, string $template, ?array $dat
     {
         $data ??= [];
         $mailer = $this->constructPHPMailer();
+
+        $twig = $this->constructTwigEnvironment();
+        $twig->addFunction(new TwigFunction("setSubject", fn($x) => ($mailer->Subject = $x)));
+
         $mailer->setFrom($this->MSG_SENDER_EMAIL, $this->MSG_SENDER_NAME);
         $mailer->addReplyTo($this->MSG_SUPPORT_EMAIL, $this->MSG_SUPPORT_NAME);
 
-        $mes_html = $this->twig->render("$template.html.twig", $data);
+        $mes_html = $twig->render("$template.html.twig", $data);
         $mailer->msgHTML($mes_html);
 
         if ($recipients == "admin") {

From 17040a5e923430a42c31f84ebfdc91023d4262dc Mon Sep 17 00:00:00 2001
From: Simon Leary <simon.leary42@proton.me>
Date: Fri, 3 Apr 2026 13:11:35 -0400
Subject: [PATCH 5/6] reorder for diff

---
 resources/lib/UnityMailer.php | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/resources/lib/UnityMailer.php b/resources/lib/UnityMailer.php
index f0b72bf49..e1fcf5924 100644
--- a/resources/lib/UnityMailer.php
+++ b/resources/lib/UnityMailer.php
@@ -104,12 +104,12 @@ public function constructTwigEnvironment(): \Twig\Environment
      */
     public function sendMail(string|array $recipients, string $template, ?array $data = null): void
     {
-        $data ??= [];
         $mailer = $this->constructPHPMailer();
 
         $twig = $this->constructTwigEnvironment();
         $twig->addFunction(new TwigFunction("setSubject", fn($x) => ($mailer->Subject = $x)));
 
+        $data ??= [];
         $mailer->setFrom($this->MSG_SENDER_EMAIL, $this->MSG_SENDER_NAME);
         $mailer->addReplyTo($this->MSG_SUPPORT_EMAIL, $this->MSG_SUPPORT_NAME);
 

From 9783ac35b80b8a37f8f9fe93481d60111c3567fd Mon Sep 17 00:00:00 2001
From: Simon Leary <simon.leary42@proton.me>
Date: Fri, 3 Apr 2026 13:15:45 -0400
Subject: [PATCH 6/6] private

---
 resources/lib/UnityMailer.php | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/resources/lib/UnityMailer.php b/resources/lib/UnityMailer.php
index e1fcf5924..106cb722b 100644
--- a/resources/lib/UnityMailer.php
+++ b/resources/lib/UnityMailer.php
@@ -32,7 +32,7 @@ public function __construct()
         $this->MSG_PI_APPROVAL_NAME = CONFIG["mail"]["pi_approve_name"];
     }
 
-    public function constructPHPMailer(): PHPMailer
+    private function constructPHPMailer(): PHPMailer
     {
         $mailer = new PHPMailer(exceptions: true);
         $mailer->isSMTP();
@@ -79,7 +79,7 @@ public function constructPHPMailer(): PHPMailer
         return $mailer;
     }
 
-    public function constructTwigEnvironment(): \Twig\Environment
+    private function constructTwigEnvironment(): \Twig\Environment
     {
         $loader = new \Twig\Loader\FilesystemLoader([
             __DIR__ . "/../../deployment/mail_overrides",