diff --git a/api/src/Mail.php b/api/src/Mail.php
index 811aab2f32..c98d4a66e4 100644
--- a/api/src/Mail.php
+++ b/api/src/Mail.php
@@ -5611,7 +5611,7 @@ class Mail
 			if (is_object($mail))
 			{
 				$structure = $mail->getStructure();
-				$isSmime = Mail\Smime::isSmime($structure->getType());
+				$isSmime = Mail\Smime::isSmime($structure->getType()) || Mail\Smime::isSmimeSignatureOnly($structure->getType());
 				if ($isSmime)
 				{
 					return $this->resolveSmimeMessage($structure, array(
@@ -7349,13 +7349,19 @@ class Mail
 		$message = $this->getMessageRawBody($params['uid'], null, $params['mailbox']);
 		if (!Mail\Smime::isSmimeSignatureOnly($params['mimeType']))
 		{
-			$message = $this->_decryptSmimeBody($message, $params['passphrase'] !='' ?
-					$params['passphrase'] : Api\Cache::getSession('mail', 'smime_passphrase'));
+			try{
+				$message = $this->_decryptSmimeBody($message, $params['passphrase'] !='' ?
+						$params['passphrase'] : Api\Cache::getSession('mail', 'smime_passphrase'));
+			}
+			catch(\Horde_Crypt_Exception $e)
+			{
+				throw new Mail\Smime\PassphraseMissing(lang('Could not decrypt S/MIME data. This message may not be encrypted by your public key.'));
+			}
 			$metadata['encrypted'] = true;
 		}
 
 		try {
-			$cert = $this->smime->verify($message);
+			$cert = $this->smime->verifySignature($message);
 		} catch (\Exception $ex) {
 			// passphrase is required to decrypt the message
 			if (isset($message['password_required']))
diff --git a/api/src/Mail/Smime.php b/api/src/Mail/Smime.php
index e38661375f..781c7e1c28 100644
--- a/api/src/Mail/Smime.php
+++ b/api/src/Mail/Smime.php
@@ -39,6 +39,7 @@ class Smime extends Horde_Crypt_Smime
 	static $SMIME_SIGNATURE_ONLY_TYPES = array (
 		'application/x-pkcs7-signature',
 		'application/pkcs7-signature',
+		'multipart/signed'
 	);
 
 	/**
@@ -180,4 +181,20 @@ class Smime extends Horde_Crypt_Smime
         return Horde_Mime_Part::parseMessage(parent::extractSignedContents($data), array('forcemime' => true));
     }
 
+	/**
+	 * Verify a signature
+	 *
+	 * @param type $message
+	 * @return type
+	 */
+	public function verifySignature($message)
+	{
+		$cert_locations = openssl_get_cert_locations();
+		$certs = array();
+		foreach (scandir($cert_locations['default_cert_dir']) as &$file)
+		{
+			if (!is_dir($cert_locations['default_cert_dir'].'/'.$file)) $certs[]= $cert_locations['default_cert_dir'].'/'.$file;
+		}
+		return $this->verify($message, $certs);
+	}
 }
diff --git a/mail/inc/class.mail_ui.inc.php b/mail/inc/class.mail_ui.inc.php
index 4d53527f0e..b95efac722 100644
--- a/mail/inc/class.mail_ui.inc.php
+++ b/mail/inc/class.mail_ui.inc.php
@@ -3070,7 +3070,12 @@ $filter['before']= date("d-M-Y", $cutoffdate2);
 		{
 			if ($smimePassphrase)
 			{
-				Api\Cache::setSession('mail', 'smime_passphrase', $smimePassphrase);
+				if ($this->mail_bo->mailPreferences['smime_pass_exp'] != $_POST['smime_pass_exp'])
+				{
+					$GLOBALS['egw']->preferences->add('mail', 'smime_pass_exp', $_POST['smime_pass_exp']);
+					$GLOBALS['egw']->preferences->save_repository();
+				}
+				Api\Cache::setSession('mail', 'smime_passphrase', $smimePassphrase, $_POST['smime_pass_exp'] * 60);
 			}
 			$structure = $this->mail_bo->getStructure($uid, $partID, $mailbox, false);
 			if (($smime = $structure->getMetadata('X-EGroupware-Smime')))
@@ -3092,7 +3097,7 @@ $filter['before']= date("d-M-Y", $cutoffdate2);
 			{
 				self::callWizard($e->getMessage().' '.lang('Please configure your S/MIME private key in Encryption tab located at Edit Account dialog.'));
 			}
-
+			Framework::message($e->getMessage());
 			// do NOT include any default CSS
 			$smimeHtml = $this->get_email_header().
 			'<div class="smime-message">'.lang("This message is smime encrypted and password protected.").'</div>'.
@@ -3102,7 +3107,10 @@ $filter['before']= date("d-M-Y", $cutoffdate2);
 						'<input type="password" placeholder="'.lang("Please enter password").'" name="smime_passphrase"/>'.
 						'<input type="submit" value="'.lang("submit").'"/>'.
 					'</div>'.
-				 '</form>';
+					'<div style="top:47%;margin-left:-15px;">'.
+						lang("Remember the password for ").'<input name="smime_pass_exp" type="number" max="60" min="1" placeholder="10" value="'.$this->mail_bo->mailPreferences['smime_pass_exp'].'"/> '.lang("minutes.").
+					'</div>'.
+			'</form>';
 			return $smimeHtml;
 		}
 		$calendar_part = null;
diff --git a/mail/js/app.js b/mail/js/app.js
index 7b88ffd046..00edb14abb 100644
--- a/mail/js/app.js
+++ b/mail/js/app.js
@@ -998,8 +998,10 @@ app.classes.mail = AppJS.extend(
 					default:
 						widget.set_disabled(true);
 				}
+
+				this.smime_clear_flags([jQuery(widget.getDOMNode())]);
 			}
-			
+			this.smime_clear_flags([jQuery('#mail-index_mailPreviewContainer')]);
 			// Blank first, so we don't show previous email while loading
 			var IframeHandle = this.et2.getWidgetById('messageIFRAME');
 			IframeHandle.set_src('about:blank');
@@ -5815,12 +5817,36 @@ app.classes.mail = AppJS.extend(
 		if (attachmentArea) attachmentArea.getDOMNode().classList.remove('loading');
 		var smime_signature = this.et2.getWidgetById('smime_signature');
 		var smime_encryption = this.et2.getWidgetById('smime_encryption');
+		var $mail_container = egw(window).is_popup() ?
+								jQuery('.mailDisplayContainer'):
+								jQuery(this.et2.getWidgetById('mailPreviewContainer').getDOMNode());
+
+		smime_signature.set_disabled(!_data.signed);
+		smime_encryption.set_disabled(!_data.encrypted);
+		if (!_data.signed)
+		{
+			this.smime_clear_flags([$mail_container]);
+		}
+		else if (_data.verify)
+		{
+			$mail_container.addClass('smime_cert_verified');
+			smime_signature.set_class('smime_cert_verified');
+		}
+		else if (!_data.verify)
+		{
+			$mail_container.addClass('smime_cert_notverified');
+			smime_signature.set_class('smime_cert_notverified');
+			smime_signature.set_statustext(_data.msg);
+		}
+	},
+
+	smime_clear_flags: function (_nodes)
+	{
+		for(var i=0;i<_nodes.length;i++)
+		{
+			var smime_classes = 'smime_cert_verified smime_cert_notverified';
+			_nodes[i].removeClass(smime_classes);
+		}
 
-			smime_signature.set_disabled(!_data.signed);
-			smime_encryption.set_disabled(!_data.encrypted);
-			if (!_data.verify)
-			{
-				smime_signature.set_statustext(_data.msg);
-			}
 	}
 });
diff --git a/mail/templates/default/app.css b/mail/templates/default/app.css
index b20b52de8d..42b4a8c2d3 100644
--- a/mail/templates/default/app.css
+++ b/mail/templates/default/app.css
@@ -911,4 +911,23 @@ div.mailComposeHeaderSection>table {
 #mail-compose_mailaccount {max-width: 100% !important;}
 
 .header_row_right.vertical_splitter {float:left;}
-.header_row_right.vertical_splitter div#mail-index_mail-index-vacationnotice .et2_vbox {margin-right: 0;}
\ No newline at end of file
+.header_row_right.vertical_splitter div#mail-index_mail-index-vacationnotice .et2_vbox {margin-right: 0;}
+
+div.smime_cert_notverified {
+	border-top: 4px solid lightgreen !important;
+}
+img.smime_cert_notverified {
+	background: lightgreen !important;
+}
+div.smime_cert_verified {
+	border-top: 4px solid green;
+}
+img.smime_cert_verified {
+	background: green;
+}
+div.smime_cert_notvalid {
+	border-top: 4px solid red;
+}
+img.smime_cert_notvalid {
+	background: red;
+}
\ No newline at end of file
diff --git a/mail/templates/mobile/app.css b/mail/templates/mobile/app.css
index 867ae31aaa..240938765a 100644
--- a/mail/templates/mobile/app.css
+++ b/mail/templates/mobile/app.css
@@ -901,6 +901,24 @@ div.mailComposeHeaderSection > table {
 .header_row_right.vertical_splitter div#mail-index_mail-index-vacationnotice .et2_vbox {
   margin-right: 0;
 }
+div.smime_cert_notverified {
+  border-top: 4px solid lightgreen !important;
+}
+img.smime_cert_notverified {
+  background: lightgreen !important;
+}
+div.smime_cert_verified {
+  border-top: 4px solid green;
+}
+img.smime_cert_verified {
+  background: green;
+}
+div.smime_cert_notvalid {
+  border-top: 4px solid red;
+}
+img.smime_cert_notvalid {
+  background: red;
+}
 #popupMainDiv {
   padding: 5px;
 }
diff --git a/mail/templates/pixelegg/app.css b/mail/templates/pixelegg/app.css
index 6a94edc0af..eb2ea6af5f 100755
--- a/mail/templates/pixelegg/app.css
+++ b/mail/templates/pixelegg/app.css
@@ -889,6 +889,24 @@ div.mailComposeHeaderSection > table {
 .header_row_right.vertical_splitter div#mail-index_mail-index-vacationnotice .et2_vbox {
   margin-right: 0;
 }
+div.smime_cert_notverified {
+  border-top: 4px solid lightgreen !important;
+}
+img.smime_cert_notverified {
+  background: lightgreen !important;
+}
+div.smime_cert_verified {
+  border-top: 4px solid green;
+}
+img.smime_cert_verified {
+  background: green;
+}
+div.smime_cert_notvalid {
+  border-top: 4px solid red;
+}
+img.smime_cert_notvalid {
+  background: red;
+}
 #popupMainDiv {
   padding: 5px;
 }
diff --git a/mail/templates/pixelegg/app.less b/mail/templates/pixelegg/app.less
index aaa8b4ca16..617f425c6f 100755
--- a/mail/templates/pixelegg/app.less
+++ b/mail/templates/pixelegg/app.less
@@ -76,7 +76,7 @@ body {
 				select {margin-top: 9px;}
 			} // Ende Filter
 		} // Ende Header
-		
+
 		// Bilder in den Listen
 		tr.mail td img {
 			max-height: 50px;