Invites are not beeing send

[krestensb]

Baikal version 0.9.5

I have installed Baikal as explained in https://sabre.io/baikal/install/ and calendar sync is working fine.

However, if I try to send an invite from an event, nothing happens.
I would expect that an e-mail would be send.
I don't see any error either.

Under Baïkal system settings, Email invite sender address is set.
Am I missing any further needed setup, or is there any way I can debug this problem?

I have these plugins activated:

Adds support for WebDAV ACL (rfc3744) |  
Generates HTML indexes and debug information for your sabre/dav server |  
This plugin allows any arbitrary WebDAV property to be set on any resource. |  
Adds support for WebDAV Collection Sync (rfc6578) |  
Adds support for CalDAV (rfc4791) |  
Adds the ability to export CalDAV calendars as a single iCalendar file. |  
Adds calendar-auto-schedule, as defined in rfc6638 |  
This plugin implements WebDAV resource sharing |  
Adds support for caldav-sharing. |  
Email delivery (rfc6047) for CalDAV scheduling |  
Adds support for CardDAV (rfc6352) |  
Adds the ability to export CardDAV addressbooks as a single vCard file. |  

\Kresten