I just did a manual upgrade to D8.8.1 using the recommended-project layout following the instructions here: https://www.drupal.org/docs/8/install/add-composer-to-an-existing-site.
All my contributed modules are in 'newsite/web/modules/contrib'. I tried to do a test of the new design by using composer to install a new module, redirect.
I am running CentOS 7.7 x86 architecture with Drupal 8.7.10, php72u-7.2.25-1.el7.ius.x86_64 version, composer version is 1.9.1, nginx web server version is 1.16.1. I am facing the below issue.
I made a new site from scratch using the new template, and installing every module using composer. I have 3 Mail modules installed: PHPMailer, Swiftmailer, and mailsystem. But after configuring all of these properly, mail does not get sent. There are NO log error messages, nor are there any on drush watchdog-show. And PHPmailer is NOT writing out any logs or messages even though the debug level is Full Communication, and write to system logs is checked. The PHPMailer GUI says a test email has been sent.