If you are using the FluentSMTP plugin for sending site emails using a transactional email provider such as AWS SES, Postmark, Sendinblue, SendGrid, or SparkPost then the logs database table could cause a lot of bloat on your site.
The below database table for FluentSMTP logs could increase to 5-12 GB in size:
WP-Optimize > Database > Tables
Then search for fsmpt or fluent, and the plugin will find the table and show you how many records are stored and the table size.
The phpMyAdmin application is provided on most hosts, and you can search by both the database table and sort by the largest tables in the database. Within the phpMyAdmin interface, you can set the FluentSMTP email logs database table to be emptied.
The FluentSMTP plugin does not have any settings controls for email log retention, you can only disable email logging in wp-admin;
Settings > FluentSMTP > Settings
The FluentSMTP plugin is a solid plugin for integrating with several transactional email providers for sending out site emails such as forgot passwords, registration, etc. but keeping an eye on email logs database size will keep your site’s database from becoming bloated.