Ojs 3 email problem

Hi to all, i am new tiwh ojs 3 and in general web site managment.
I installed ojs 3 on a ubuntu machine and it seems to work except for mail sending
I modify the config.inc.php in this way but the system doe not send any email

; Use SMTP for sending mail instead of mail()
; smtp = On

; SMTP server settings
; smtp_server = “smtp.gmail.com
; smtp_port = 465

; Enable SMTP authentication
; Supported mechanisms: ssl, tls
; smtp_auth = ssl
; smtp_username = jour…
; smtp_password = lukfk…

In the error log i read:

[Mon Sep 10 12:38:47.128329 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of PKPUsageEventPlugin::getEnabled() should be compatible with LazyLoadPlugin::getEnabled($contextId = NULL) in /var/www/html/lib/pkp/plugins/generic/usageEvent/PKPUsageEventPlugin.inc.php on line 0, referer: http://localhost/index.php/PROVA/management/settings/access
[Mon Sep 10 12:38:47.137264 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of UserGridHandler::renderFilter($request) should be compatible with GridHandler::renderFilter($request, $filterData = Array) in /var/www/html/lib/pkp/controllers/grid/settings/user/UserGridHandler.inc.php on line 0, referer: http://localhost/index.php/PROVA/management/settings/access
[Mon Sep 10 12:38:47.137660 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of UserForm::display($args, $request) should be compatible with Form::display($request = NULL, $template = NULL) in /var/www/html/lib/pkp/controllers/grid/settings/user/form/UserForm.inc.php on line 18, referer: http://localhost/index.php/PROVA/management/settings/access
[Mon Sep 10 12:38:47.137673 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of UserForm::initData($args, $request) should be compatible with Form::initData() in /var/www/html/lib/pkp/controllers/grid/settings/user/form/UserForm.inc.php on line 18, referer: http://localhost/index.php/PROVA/management/settings/access
[Mon Sep 10 12:38:47.137677 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of UserForm::execute($args, $request) should be compatible with Form::execute() in /var/www/html/lib/pkp/controllers/grid/settings/user/form/UserForm.inc.php on line 18, referer: http://localhost/index.php/PROVA/management/settings/access
[Mon Sep 10 12:38:47.142241 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of UserEmailForm::fetch($args, $request) should be compatible with Form::fetch($request, $template = NULL, $display = false) in /var/www/html/lib/pkp/controllers/grid/settings/user/form/UserEmailForm.inc.php on line 0, referer: http://localhost/index.php/PROVA/management/settings/access
[Mon Sep 10 12:38:47.142262 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of UserEmailForm::execute($args, $request) should be compatible with Form::execute() in /var/www/html/lib/pkp/controllers/grid/settings/user/form/UserEmailForm.inc.php on line 0, referer: http://localhost/index.php/PROVA/management/settings/access
sh: 1: /usr/sbin/sendmail: not found
[Mon Sep 10 12:38:47.148849 2018] [php7:notice] [pid 13026] [client 127.0.0.1:51104] Could not instantiate mail function., referer: http://localhost/index.php/PROVA/management/settings/access
[Mon Sep 10 12:38:47.191114 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of PKPUsageEventPlugin::getEnabled() should be compatible with LazyLoadPlugin::getEnabled($contextId = NULL) in /var/www/html/lib/pkp/plugins/generic/usageEvent/PKPUsageEventPlugin.inc.php on line 0, referer: http://localhost/index.php/PROVA/management/settings/access
[Mon Sep 10 12:38:47.242413 2018] [php7:warn] [pid 13026] [client 127.0.0.1:51104] PHP Warning: Declaration of PKPUsageEventPlugin::getEnabled() should be compatible with LazyLoadPlugin::getEnabled($contextId = NULL) in /var/www/html/lib/pkp/plugins/generic/usageEvent/PKPUsageEventPlugin.inc.php on line 0, referer: http://localhost/index.php/PROVA/management/settings/access

Hi @luca,

Welcome to the OJS community! There are a number of questions in our FAQ about troubleshooting email setup and delivery. Please take a look at this.

Thanks,
Amanda Stevens
Public Knowledge Project Team