Activating mails: It is possible to define wrong value in the send from input

503 r18749

During the install wizard, I have activated mail service. I have entered bad values in the send to input. No problem, until the first time a mail is sent (exception raised because email adress contains blank spaces). I have then updated my wrong value in admin center, and entered an other wrong value (still not a valid email adress, but no blank space this time). No problem when saving, but same exception when a mail is sent (exception because of blanks). Value was well updated in admin center, so I conclude that I need to restart jahia so that the new value is used. Still same pb, and in admin center, I see the old value, which means that it wasn't really updated whereas nothing indicated it. Then I enter a valid value, this time I am displayed a message which informs me that value has been well updated and will be used after next reboot.

So:
_ please add a check when defining sent to adress in install wizard and in admin center to refuse invalid values, and warn user about it (probably same pb with "send from" adress)
_ can we define more than one destination adress? (maybe separated by semicolon like in emails) In this case, add a message near input field to indicate it to user.
_ is it absolutely necessary to wait for next reboot?