you can try this code, add it to functions.php of the theme

function my_mail_from( $email )
{
return ‘no-replay@your-site.com’;
}
add_filter( ‘wp_mail_from’, ‘my_mail_from’ );
function my_mail_from_name( $name )
{
return ‘Contact’;
}
add_filter( ‘wp_mail_from_name’, ‘my_mail_from_name’ );

Former, my WP site sent email correctly (use PHP function). After upgrading to WP network multisites, my wordpress do not send any email to my mailbox (I use Gmail).

Please suggest me to solve this issue.

SMTP -> ERROR: Failed to connect to server: A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.
(10060)

Have any suggestions for either solution to resolve the WP not sending email?

Also both setup have wp-mail-smtp enabled.