When I use smtp.gmail.com to send invitations and reminders, the "from" address is changed from the survey administrator email address to the address of the account used to authenticate the SMTP connection. When a survey participant clicks on the reply button in email, the message is address to the SMTP account instead of the survey administrator.   See the related discussion in the forum .

Adding a "reply-to" header at the same time that the "From" address is set (LimeMailer.php, line 529 in version 5.1.10+210913) gives me the behavior I want (when the participant clicks the reply button in email, the message is address to the survey administrator).

Please consider adding the "reply-to" header to future versions.
 

Already included in the core plugin ? No ?

Please : when it's not used by a lot of people : do it in plugin. LimeSurvey core is already so complex to evolve easily …