Email : Message body empty

Hello,
I am new user of Projeqtor (previous: dotproject).
I have right install and think well config.
Our web site is host by OVH (Apache 1.3, PHP Version 5.6.21)

I've got a difficulty with mail. I clic on "Send information to user" send their login/password by mail and I got error message : "Not able to send mail to 'ww@yy' ask admin.
In the log i have :
2016-12-25 20:37:23.179 ***** ERROR ***** Error sending mail
2016-12-25 20:37:23.181 ***** ERROR ***** SMTP Server : smtp.yy.fr
2016-12-25 20:37:23.182 ***** ERROR ***** SMTP Port : 587
2016-12-25 20:37:23.183 ***** ERROR ***** Mail stored in Database : #20
2016-12-25 20:37:23.183 ***** ERROR ***** PHPMail error : Message body empty
2016-12-25 20:37:23.184 ***** ERROR ***** PHPMail debug :

So mail was not sent, in the windows "Email sent", the sent statut is "error" (see png joined)

BUT I received a mail when I have create and assight an activity by request to sent a mail to requestor ....

I searched in yours forum, test to modify parameters.php : $paramMailerType='mail';

Config Emailing
email of administrator : myemail
'from' email when sending mails : myemail
'reply to' email when sending mails : myemail
name of sender and reply to : My name
smtp server : smtp.yyy.fr
smtp port : 587
smtp login name : myemail
smtp login password : password
end of line format for mail : default format (\r\n)
sendmail path : empty

I found any way to solve this mail error.
If someone have idea

Thank you for answer
Yes I do
I dont find anything except that the Messagebody is empty
I attach the 1st log (modified on my domain)

Log file