Ok ! I found something !
Thanks for your question “What has changed?”
Effectively, recently, one month ago I think, I reinstalled my SMTP server, so I tried something : send a message with telnet and this smtp.I noticed that it was taking a few seconds to accept sender and recipient address : The first DNS server on this machine was invalid.
Once the DNS server has been corrected, new calendar event are saved in “few” seconds, instead of minutes…
BUT, I’m really surprised…this emails should be sent async, many problems can occur and shouldn’t block the GUI .
Furthermore, the freeze is directly dependent of the number of participants,even if emails are sent quickly.
However thank you for this program, it’s a beautiful work.