strlen() was used in Phabricator to check if a generic value is a non-empty string.
This behavior is deprecated since PHP 8.1. Phorge adopts phutil_nonempty_string() as a replacement.
ERROR 8192: strlen(): Passing null to parameter #1 ($string) of type string is deprecated at [/var/www/htdocs/phorge/phorge/src/applications/metamta/adapter/PhabricatorMailSMTPAdapter.php:65]
Closes T15857