diff --git a/mail/inc/class.mail_compose.inc.php b/mail/inc/class.mail_compose.inc.php
index 75b12ed1c1..64b6994e0d 100644
--- a/mail/inc/class.mail_compose.inc.php
+++ b/mail/inc/class.mail_compose.inc.php
@@ -2159,6 +2159,10 @@ class mail_compose
 	 */
 	function createMessage(egw_mailer $_mailObject, array $_formData, array $_identity, $_autosaving=false)
 	{
+		if (substr($_formData['body'], 0, 27) == '-----BEGIN PGP MESSAGE-----')
+		{
+			$_formData['mimeType'] = 'openpgp';
+		}
 		//error_log(__METHOD__."(, formDate[filemode]=$_formData[filemode], _autosaving=".array2string($_autosaving).') '.function_backtrace());
 		$mail_bo	= $this->mail_bo;
 		$activeMailProfile = emailadmin_account::read($this->mail_bo->profileID);
@@ -2292,6 +2296,10 @@ class mail_compose
 			}
 			$_mailObject->setHtmlBody($body, null, false);	// false = no automatic alternative, we called setBody()
 		}
+		elseif ($_formData['mimeType'] == 'openpgp')
+		{
+			$_mailObject->setOpenPgpBody($_formData['body']);
+		}
 		else
 		{
 			$body = $this->convertHTMLToText($_formData['body'],false);
diff --git a/phpgwapi/inc/class.egw_mailer.inc.php b/phpgwapi/inc/class.egw_mailer.inc.php
index 184e784ab6..b432760586 100644
--- a/phpgwapi/inc/class.egw_mailer.inc.php
+++ b/phpgwapi/inc/class.egw_mailer.inc.php
@@ -453,7 +453,8 @@ class egw_mailer extends Horde_Mime_Mail
 		), array(), true);	// true = call all apps
 
 		try {
-			parent::send($this->account->smtpTransport(), true);	// true: keep Message-ID
+			parent::send($this->account->smtpTransport(), true,		// true: keep Message-ID
+				$this->_body->getType() != 'multipart/encrypted');	// no flowed for encrypted messages
 		}
 		catch (Exception $e) {
 			// in case of errors/exceptions call hook again with previous returned mail_id and error-message to log
@@ -632,6 +633,32 @@ class egw_mailer extends Horde_Mime_Mail
 		return parent::addMimePart($part);
 	}
 
+	/**
+	 * Sets OpenPGP encrypted body according to rfc3156, section 4
+	 *
+	 * @param string $body             The message content.
+	 * @link https://tools.ietf.org/html/rfc3156#section-4
+	 */
+	public function setOpenPgpBody($body)
+	{
+		$this->_body = new Horde_Mime_Part();
+		$this->_body->setType('multipart/encrypted');
+		$this->_body->setContentTypeParameter('protocol', 'application/pgp-encrypted');
+		$this->_body->setContents('');
+
+		$part1 = new Horde_Mime_Part();
+		$part1->setType('application/pgp-encrypted');
+		$part1->setContents("Version: 1\r\n", array('encoding' => '7bit'));
+		$this->_body->addPart($part1);
+
+		$part2 = new Horde_Mime_Part();
+		$part2->setType('application/octet-stream');
+		$part2->setContents($body, array('encoding' => '7bit'));
+		$this->_body->addPart($part2);
+
+		$this->_base = null;
+	}
+
 	/**
 	 * Clear all non-standard headers
 	 *