diff --git a/rainloop/v/0.0.0/app/libraries/MailSo/Base/Utils.php b/rainloop/v/0.0.0/app/libraries/MailSo/Base/Utils.php
index 70fd3793c..4c3699739 100644
--- a/rainloop/v/0.0.0/app/libraries/MailSo/Base/Utils.php
+++ b/rainloop/v/0.0.0/app/libraries/MailSo/Base/Utils.php
@@ -1254,6 +1254,40 @@ class Utils
 		return \MailSo\Base\Utils::Base64Decode($sData);
 	}
 
+	/**
+	 * @param string $sSequence
+	 *
+	 * @return array
+	 */
+	public static function ExpandFetchSequence($sSequence)
+	{
+		$aResult = array();
+		$sSequence = \trim($sSequence);
+		if (0 < \strlen($sSequence))
+		{
+			$aSequence = \explode(',', $sSequence);
+			foreach ($aSequence as $sItem)
+			{
+				if (false === \strpos($sItem, ':'))
+				{
+					$aResult[] = (int) $sItem;
+				}
+				else
+				{
+					$aItems = \explode(':', $sItem);
+					$iMax = \max($aItems[0], $aItems[1]);
+
+					for ($iIndex = $aItems[0]; $iIndex <= $iMax; $iIndex++)
+					{
+						$aResult[] = (int) $iIndex;
+					}
+				}
+			}
+		}
+
+		return $aResult;
+	}
+
 	/**
 	 *
 	 * @param resource $fResource
diff --git a/rainloop/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php b/rainloop/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
index 5cee16823..31d1a6ff4 100644
--- a/rainloop/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
+++ b/rainloop/v/0.0.0/app/libraries/MailSo/Imap/ImapClient.php
@@ -1039,9 +1039,102 @@ class ImapClient extends \MailSo\Net\NetClient
 		return $aReturn;
 	}
 
+	/**
+	 * @param string $sSearchCriterias = 'ALL'
+	 * @param array $aSearchReturn = null
+	 * @param bool $bReturnUid = true
+	 * @param string $sLimit = ''
+	 * @param string $sCharset = ''
+	 *
+	 * @return array
+	 *
+	 * @throws \MailSo\Base\Exceptions\InvalidArgumentException
+	 * @throws \MailSo\Net\Exceptions\Exception
+	 * @throws \MailSo\Imap\Exceptions\Exception
+	 */
+	public function MessageSimpleESearch($sSearchCriterias = 'ALL', $aSearchReturn = null, $bReturnUid = true, $sLimit = '', $sCharset = '')
+	{
+		$sCommandPrefix = ($bReturnUid) ? 'UID ' : '';
+		$sSearchCriterias = 0 === \strlen($sSearchCriterias) || '*' === $sSearchCriterias
+			? 'ALL' : $sSearchCriterias;
+
+		if (!$this->IsSupported('ESEARCH'))
+		{
+			$this->writeLogException(
+				new \MailSo\Base\Exceptions\InvalidArgumentException(),
+				\MailSo\Log\Enumerations\Type::ERROR, true);
+		}
+
+		if (!\is_array($aSearchReturn) || 0 === \count($aSearchReturn))
+		{
+			$aSearchReturn = array('ALL');
+		}
+
+		$aRequest = array();
+		if (0 < \strlen($sCharset))
+		{
+			$aRequest[] = 'CHARSET';
+			$aRequest[] = \strtoupper($sCharset);
+		}
+
+		$aRequest[] = 'RETURN';
+		$aRequest[] = $aSearchReturn;
+
+		$aRequest[] = $sSearchCriterias;
+		
+		if (0 < \strlen($sLimit))
+		{
+			$aRequest[] = $sLimit;
+		}
+
+		$this->SendRequest($sCommandPrefix.('SEARCH'), $aRequest);
+		$sRequestTag = $this->getCurrentTag();
+
+		$aResult = array();
+		$aResponse = $this->parseResponseWithValidation();
+		
+		if (\is_array($aResponse))
+		{
+			$oImapResponse = null;
+			foreach ($aResponse as /* @var $oImapResponse \MailSo\Imap\Response */ $oImapResponse)
+			{
+				if (\MailSo\Imap\Enumerations\ResponseType::UNTAGGED === $oImapResponse->ResponseType
+					&& 'ESEARCH' === $oImapResponse->StatusOrIndex
+					&& \is_array($oImapResponse->ResponseList)
+					&& isset($oImapResponse->ResponseList[2], $oImapResponse->ResponseList[2][0], $oImapResponse->ResponseList[2][1])
+					&& 'TAG' === $oImapResponse->ResponseList[2][0] && $sRequestTag === $oImapResponse->ResponseList[2][1]
+					&& (!$bReturnUid || ($bReturnUid && !empty($oImapResponse->ResponseList[3]) && 'UID' === $oImapResponse->ResponseList[3]))
+				)
+				{
+					$iStart = 3;
+					foreach ($oImapResponse->ResponseList as $iIndex => $mItem)
+					{
+						if ($iIndex >= $iStart)
+						{
+							switch ($mItem)
+							{
+								case 'ALL':
+								case 'MAX':
+								case 'MIN':
+								case 'COUNT':
+									if (isset($oImapResponse->ResponseList[$iIndex + 1]))
+									{
+										$aResult[$mItem] = $oImapResponse->ResponseList[$iIndex + 1];
+									}
+									break;
+							}
+						}
+					}
+				}
+			}
+		}
+
+		return $aResult;
+	}
+
 	/**
 	 * @param string $sSearchCriterias
-	 * @param bool $bReturnUid
+	 * @param bool $bReturnUid = true
 	 * @param string $sCharset = ''
 	 *
 	 * @return array
diff --git a/rainloop/v/0.0.0/app/libraries/MailSo/Mail/MailClient.php b/rainloop/v/0.0.0/app/libraries/MailSo/Mail/MailClient.php
index 1bd221972..729e9233b 100644
--- a/rainloop/v/0.0.0/app/libraries/MailSo/Mail/MailClient.php
+++ b/rainloop/v/0.0.0/app/libraries/MailSo/Mail/MailClient.php
@@ -1520,6 +1520,7 @@ class MailClient
 	 * @param bool $bUseSortIfSupported = false
 	 * @param bool $bUseThreadSortIfSupported = false
 	 * @param array $aExpandedThreadsUids = array()
+	 * @param bool $bUseESearchOrESortRequest = true
 	 *
 	 * @return \MailSo\Mail\MessageCollection
 	 *
@@ -1528,7 +1529,8 @@ class MailClient
 	 * @throws \MailSo\Imap\Exceptions\Exception
 	 */
 	public function MessageList($sFolderName, $iOffset = 0, $iLimit = 10, $sSearch = '', $sPrevUidNext = '',
-		$oCacher = null, $bUseSortIfSupported = false, $bUseThreadSortIfSupported = false, $aExpandedThreadsUids = array())
+		$oCacher = null, $bUseSortIfSupported = false, $bUseThreadSortIfSupported = false, $aExpandedThreadsUids = array(),
+		$bUseESearchOrESortRequest = true)
 	{
 		$sSearch = \trim($sSearch);
 		if (!\MailSo\Base\Validator::RangeInt($iOffset, 0) ||
@@ -1555,7 +1557,9 @@ class MailClient
 		$iMessageCacheCount = 100;
 		$sUidNext = '0';
 		$sSerializedHash = '';
+		$bESearchSupported = $bUseESearchOrESortRequest ? $this->oImapClient->IsSupported('ESEARCH') : false;
 		$bUseSortIfSupported = $bUseSortIfSupported ? $this->oImapClient->IsSupported('SORT') : false;
+		$bESortSupported = $bUseSortIfSupported && $bUseESearchOrESortRequest ? $this->oImapClient->IsSupported('ESORT') : false;
 		$bUseThreadSortIfSupported = $bUseThreadSortIfSupported ?
 			($this->oImapClient->IsSupported('THREAD=REFS') || $this->oImapClient->IsSupported('THREAD=REFERENCES') || $this->oImapClient->IsSupported('THREAD=ORDEREDSUBJECT')) : false;
 
@@ -1584,7 +1588,6 @@ class MailClient
 			if ($bSearch || ($bUseSortIfSupported && !$bUseThreadSortIfSupported))
 			{
 				$bIndexAsUid = true;
-
 				$aIndexOrUids = null;
 
 				$sSearchCriterias = $this->getSearchBuilder($sSearch)->Complete();
@@ -1618,7 +1621,15 @@ class MailClient
 				{
 					if ($bUseSortIfSupported && !$bUseThreadSortIfSupported)
 					{
-						$aIndexOrUids = $this->oImapClient->MessageSimpleSort(array('ARRIVAL'), $sSearchCriterias, $bIndexAsUid);
+						if ($bESortSupported)
+						{
+							// TODO
+							$aIndexOrUids = $this->oImapClient->MessageSimpleSort(array('ARRIVAL'), $sSearchCriterias, $bIndexAsUid);
+						}
+						else
+						{
+							$aIndexOrUids = $this->oImapClient->MessageSimpleSort(array('ARRIVAL'), $sSearchCriterias, $bIndexAsUid);
+						}
 					}
 					else
 					{
@@ -1626,7 +1637,18 @@ class MailClient
 						{
 							try
 							{
-								$aIndexOrUids = $this->oImapClient->MessageSimpleSearch($sSearchCriterias, $bIndexAsUid, 'UTF-8');
+								if ($bESearchSupported)
+								{
+									$aESearchData = $this->oImapClient->MessageSimpleESearch($sSearchCriterias, array('ALL'), $bIndexAsUid, '', 'UTF-8');
+									if (isset($aESearchData['ALL']))
+									{
+										$aIndexOrUids = \MailSo\Base\Utils::ExpandFetchSequence($aESearchData['ALL']);
+									}
+								}
+								else
+								{
+									$aIndexOrUids = $this->oImapClient->MessageSimpleSearch($sSearchCriterias, $bIndexAsUid, 'UTF-8');
+								}
 							}
 							catch (\MailSo\Imap\Exceptions\NegativeResponseException $oException)
 							{
@@ -1637,7 +1659,18 @@ class MailClient
 
 						if (null === $aIndexOrUids)
 						{
-							$aIndexOrUids = $this->oImapClient->MessageSimpleSearch($sSearchCriterias, $bIndexAsUid);
+							if ($bESearchSupported)
+							{
+								$aESearchData = $this->oImapClient->MessageSimpleESearch($sSearchCriterias, array('ALL'), $bIndexAsUid);
+								if (isset($aESearchData['ALL']))
+								{
+									$aIndexOrUids = \MailSo\Base\Utils::ExpandFetchSequence($aESearchData['ALL']);
+								}
+							}
+							else
+							{
+								$aIndexOrUids = $this->oImapClient->MessageSimpleSearch($sSearchCriterias, $bIndexAsUid);
+							}
 						}
 					}
 				}