[Web][Tests] Add archive module tests

tests/php/Support/FakeSmtpClient.php

@@ -0,0 +1,46 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Mailcow\Tests\Support;
+
+use Mailcow\Archive\Smtp\SmtpClient;
+use Mailcow\Archive\Smtp\SmtpException;
+
+/**
+ * SmtpClient without network: records submit() and probe() calls, answers with the configured results.
+ */
+class FakeSmtpClient extends SmtpClient
+{
+    /** @var array[] submit() calls: host, port, from, rcpt, data */
+    public array $submitted = [];
+    /** @var array[] probe() calls */
+    public array $probed = [];
+    public ?SmtpException $error = null;
+    /** @var string[] extensions probe() reports */
+    public array $extensions = ['PIPELINING', 'SIZE', 'STARTTLS', '8BITMIME', 'SMTPUTF8'];
+    public array $mx = [];
+
+    public function submit(string $host, int $port, string $from, string $rcpt, string $data): string
+    {
+        if ($this->error !== null) {
+            throw $this->error;
+        }
+        $this->submitted[] = compact('host', 'port', 'from', 'rcpt', 'data');
+        return 'Q' . count($this->submitted);
+    }
+
+    public function probe(string $host, int $port, string $tls, string $username, string $password, string $from, string $rcpt): array
+    {
+        $this->probed[] = compact('host', 'port', 'tls', 'username', 'password', 'from', 'rcpt');
+        if ($this->error !== null) {
+            throw $this->error;
+        }
+        return $this->extensions;
+    }
+
+    public function mailHost(string $domain): string
+    {
+        return $this->mx[$domain] ?? $domain;
+    }
+}