diff --git a/server/lib/classes/cron.d/100-monitor_email_quota.inc.php b/server/lib/classes/cron.d/100-monitor_email_quota.inc.php
index d6d55645da00b18283b98866e16bf99850a554d9..5d0c7a0bc4dc03750cba6ce1790d278698589f56 100644
--- a/server/lib/classes/cron.d/100-monitor_email_quota.inc.php
+++ b/server/lib/classes/cron.d/100-monitor_email_quota.inc.php
@@ -81,7 +81,8 @@ class cronjob_monitor_email_quota extends cronjob {
 			//* with dovecot we can use doveadm instead of 'du -s'
 			$dovecot = false;
 			if (isset($mail_config['pop3_imap_daemon']) && $mail_config ['pop3_imap_daemon'] = 'dovecot' && is_executable('doveadm')) {
-				$dovecot = true;
+				exec('doveadm quota 2>&1', $tmp_output, $tmp_retval); // with dovecot 2.2.x 'doveadm quota' is unuseable
+				if ($retval = 64) $dovecot = true;
 			}
 
 			foreach($mailboxes as $mb) {