I found the bug when the guest book data is saved. 
Автор: SHIMEI N.
Просмотрено 808,
Подписчики 1,
Размещенный 0
First I saved my guest book data to a file, and next, I changed the saving place from a file to MySQL database.
The result is that the information mail to admin can not come.
So I made another additional guest book which data is saved to MySQL database.
The result was ok, no problem.
Thank you.
Размещено
Hello. I sent a notification about your find to the company employees, expect an answer from them here in the comments.
Hello Shimei
I've tested this but it seemed to work fine for me. I believe something else must have been the reason but I am unfortunately unable to reproduce this. Can you reproduce this again by testing with a new Object? If you can, please do let me know
In any case, I will notify the developers of this so that matter remains under control
Thank you
Stefano
Автор
Thank you for answers.