Jan Štětina

This plugin shows which user has access to which posts under Users administration menu. 
User names are in columns so it is suitable only for smaller counts. Works only in conjunction with User Access Manager and requires PHP 5.3.
It was developed only as helper tool for another plugin which I am going to create in near future and I guess it can be helpful if you are interested how User Access Manager works. Plugin code is (or tries to be) well documented.
This plugin will probably not be updated any further. I provide no guarantees whatsoever.

Post Access Overview

Show who has access to which post in a single table. Works in conjunction with User Access Manager.

PhilHilton

This plugin is not affiliated with WP Forms, makers of the WP Mail SMTP plugin. Please do not bother them with support requests. It is a 3rd party solution to the lack of logging in the free version of their product.
Please bear in mind that future updates to WP Mail SMTP may break this plugin’s ability to log messages, and it may take some time for an update to be released. If they go out of their way to remove the WordPress Action Hook it depends on then an update may not be possible at all. Please use this plugin at your own risk.
This plugin has only been tested with the SMTP configuration, and not any of the other implementations provided by WP Mail SMTP. If you use it with another configuration I would be interested in hearing about you experience so that I can either confirm here that it works or make changes so that it will.

Logger for WP Mail SMTP (3rd Party)

This plugin is not affiliated with WP Forms, makers of the WP Mail SMTP plugin. Please do not bother them with support requests.

Post Access Overview vs Logger for WP Mail SMTP (3rd Party)