[kronolith] Server denied authentication

[Simon B]

Hi

Twice this week I've received the following errors emailed to me by cron...

/etc/cron.daily/kronolith:

====================

Fatal Error:
Server denied authentication.
In /usr/share/php/Horde/Smtp.php on line 433

1. Horde_Alarm->notify() /usr/bin/horde-alarms:25
2. Horde_Alarm_Handler_Mail->notify() /usr/share/php/Horde/Alarm.php:421
3. Horde_Alarm->notify() /usr/bin/horde-alarms:25
4. Horde_Alarm_Handler_Mail->notify() /usr/share/php/Horde/Alarm.php:421
5. Horde_Mime_Mail->send() /usr/share/php/Horde/Alarm/Handler/Mail.php:101
6. Horde_Mime_Part->send() /usr/share/php/Horde/Mime/Mail.php:459
7. Horde_Alarm->notify() /usr/bin/horde-alarms:25
8. Horde_Alarm_Handler_Mail->notify() /usr/share/php/Horde/Alarm.php:421
9. Horde_Mime_Mail->send() /usr/share/php/Horde/Alarm/Handler/Mail.php:101
10. Horde_Mime_Part->send() /usr/share/php/Horde/Mime/Mail.php:459
11. Horde_Mail_Transport_Smtphorde->send()
/usr/share/php/Horde/Mime/Part.php:1752
12. Horde_Alarm->notify() /usr/bin/horde-alarms:25
13. Horde_Alarm_Handler_Mail->notify() /usr/share/php/Horde/Alarm.php:421
14. Horde_Mime_Mail->send() /usr/share/php/Horde/Alarm/Handler/Mail.php:101
15. Horde_Mime_Part->send() /usr/share/php/Horde/Mime/Mail.php:459
16. Horde_Mail_Transport_Smtphorde->send()
/usr/share/php/Horde/Mime/Part.php:1752
17. Horde_Smtp->send() /usr/share/php/Horde/Mail/Transport/Smtphorde.php:134
18. Horde_Smtp->login() /usr/share/php/Horde/Smtp.php:478
19. Horde_Smtp->login() /usr/share/php/Horde/Smtp.php:399

====================
run-parts: /etc/cron.daily/kronolith exited with return code 1

Where should I start looking?  I've never had an issue with alarms in
kronolith before and I've not updated this version or made any changes on
the server this week..

Thanks

Simon