sender email address substitution

Hi everybody,
I'm running CB 2.0.10 and Joomla! 3.4.3.
I made a list of members. In the list the mail address of each member is a link to his mail address, so each registered member can send an email to another registered member. No direct email.
This works fine but,if the member receiving an email wants to reply, the reply address is wrong due to address substitution.

An example :
In my profile, my email address is like 'pseudo@orange.fr' and my login is ML
When I send a message via the CB list to another member, he receives the message from ' ML @ website' instead of 'pseudo@orange.fr' and, of course the address 'ML @ website' is invalid.
It seems to me that this problem did not occur in earlier releases of CB 2.0

Did I miss something in the paraeters or plugins and how can I suppress this address subsitution in order that the reply to a message will work ?
Many thanks in advance for any idea !
Best regards
Michel

Hello again !
I would add some precisions to my problem.
In fact the address of the sender is 'Login @ website(admin@mywebsite.fr)' where 'Login' is the login user name, say 'ML', 'website' is the Joomla! $sitename value and 'admin@mywebsite.fr' is the site email address value defined in the Joomla! configuration (PHP mail).
I upgraded today to Joomla! 3.4.4 but still the same result : the response to the message is sent to 'admin@mywebsite.fr' which is invalid.
Hope this will help
Michel

Oops !
Sorry for the false problem, only due to a wrong parameter option in the CB configuration..
In fact, in the field 'Email send by ' of the CB configuration, I choosed 'By User' instead of 'By administrator with response to user'
And this solved the problem
The problem is closed
Regards
Michel