diff --git a/snappymail/v/0.0.0/app/libraries/MailSo/Imap/Folder.php b/snappymail/v/0.0.0/app/libraries/MailSo/Imap/Folder.php
index f105e7046..7d3f4a393 100644
--- a/snappymail/v/0.0.0/app/libraries/MailSo/Imap/Folder.php
+++ b/snappymail/v/0.0.0/app/libraries/MailSo/Imap/Folder.php
@@ -105,9 +105,6 @@ class Folder
 		return 'INBOX' === \strtoupper($this->sFullName) || \in_array('\\inbox', $this->aFlagsLowerCase);
 	}
 
-	/**
-	 * @param mixed $mData
-	 */
 	public function SetMetadata(string $sName, string $sData) : void
 	{
 		$this->aMetadata[$sName] = $sData;
@@ -118,17 +115,11 @@ class Folder
 		$this->aMetadata = $aMetadata;
 	}
 
-	/**
-	 * @return mixed
-	 */
 	public function GetMetadata(string $sName) : ?string
 	{
 		return isset($this->aMetadata[$sName]) ? $this->aMetadata[$sName] : null;
 	}
 
-	/**
-	 * @return array
-	 */
 	public function Metadata() : array
 	{
 		return $this->aMetadata;
diff --git a/snappymail/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php b/snappymail/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
index e55ab992c..38cbc88c9 100644
--- a/snappymail/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
+++ b/snappymail/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
@@ -67,6 +67,7 @@ class ImapClient extends \MailSo\Net\NetClient
 	 * @var bool
 	 */
 	public $__FORCE_SELECT_ON_EXAMINE__ = false;
+	public $__DISABLE_METADATA = false;
 
 	/**
 	 * @var bool
@@ -92,7 +93,7 @@ class ImapClient extends \MailSo\Net\NetClient
 
 		parent::Connect($sServerName, $iPort, $iSecurityType, $bVerifySsl, $bAllowSelfSigned, $sClientCert);
 
-		$this->aCapabilityItems = $this->getResponse('*')->getCapabilityResult();
+		$this->setCapabilities($this->getResponse('*'));
 
 		if ($this->IsSupported('STARTTLS') && \MailSo\Net\Enumerations\ConnectionSecurityType::UseStartTLS($this->iSecurityType))
 		{
@@ -225,7 +226,7 @@ class ImapClient extends \MailSo\Net\NetClient
 					));
 			}
 
-			$this->aCapabilityItems = $oResponse->getCapabilityResult();
+			$this->setCapabilities($oResponse);
 
 			if (\strlen($sProxyAuthUser))
 			{
@@ -285,12 +286,21 @@ class ImapClient extends \MailSo\Net\NetClient
 	public function Capability() : ?array
 	{
 		if (!$this->aCapabilityItems) {
-			$this->aCapabilityItems = $this->SendRequestGetResponse('CAPABILITY')
-				->getCapabilityResult();
+			$this->setCapabilities($this->SendRequestGetResponse('CAPABILITY'));
 		}
 		return $this->aCapabilityItems;
 	}
 
+	private function setCapabilities(ResponseCollection $oResponseCollection) : void
+	{
+		$aList = $oResponseCollection->getCapabilityResult();
+		if ($aList && $this->__DISABLE_METADATA) {
+			// Issue #365: Many folders on Cyrus IMAP breaks login
+			$aList = \array_diff($aList, ['METADATA']);
+		}
+		$this->aCapabilityItems = $aList;
+	}
+
 	/**
 	 * Test support for things like:
 	 *     IMAP4rev1 IMAP4rev2 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE SORT SORT=DISPLAY
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Actions.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Actions.php
index 450a052ee..a2cd9ffe1 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Actions.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Actions.php
@@ -1234,6 +1234,7 @@ class Actions
 			}
 
 			$this->MailClient()->ImapClient()->__FORCE_SELECT_ON_EXAMINE__ = !!$this->oConfig->Get('labs', 'use_imap_force_selection');
+			$this->MailClient()->ImapClient()->__DISABLE_METADATA = !!$this->oConfig->Get('labs', 'imap_disable_metadata');
 		}
 
 		return $oAccount;
diff --git a/snappymail/v/0.0.0/app/libraries/RainLoop/Config/Application.php b/snappymail/v/0.0.0/app/libraries/RainLoop/Config/Application.php
index f108501bd..b298be84a 100644
--- a/snappymail/v/0.0.0/app/libraries/RainLoop/Config/Application.php
+++ b/snappymail/v/0.0.0/app/libraries/RainLoop/Config/Application.php
@@ -369,6 +369,7 @@ Enables caching in the system'),
 				'imap_show_login_alert' => array(true),
 				'imap_use_list_status' => array(true),
 				'imap_timeout' => array(300),
+				'imap_disable_metadata' => array(false),
 				'smtp_show_server_errors' => array(false),
 				'smtp_timeout' => array(60),
 				'sieve_auth_plain_initial' => array(true),