Jan Štětina

This plugin provides a simple API for storing miscellaneous log entries and their overview in admin area (or network 
admin area, if activated on a multisite).
Developed for private use (heavily used by my other plugins), but has perspective for more extensive usage. I can’t guarantee any support in the future nor further development, but it is to be expected. Kindly inform me about bugs, if you find any, or propose new features: <a href="mailto:zaantar@zaantar.eu?subject=[wordpress-logging-service]" rel="nofollow ugc">zaantar@zaantar.eu</a>.
See Usage and FAQ for more information.
<h3>API</h3>
Definitions:
<pre><code>WLS
</code></pre>
<ul>
<li>
should be checked before using any wls function
WLS_VERSION
</li>
<li>
should(!) contain current WLS version string
</li>
<li>
severity levels:
<pre><code>WLS_NOCATEGORY = 0

WLS_INFO = 1

WLS_NOTICE = 2

WLS_WARNING = 3

WLS_ERROR = 4

WLS_FATALERROR = 5
</code></pre>
</li>
</ul>
Functions:
<pre><code>wls_is_registered( $category_name );
</code></pre>
<ul>
<li>
returns <code>true</code>, if <code>$category_name</code> is registered
wls_register( $category_name, $description );
</li>
<li>
registers <code>$category_name</code> as a log category.
</li>
<li>
<code>$description</code> will be shown in admin area
wls_clear( $category_name );
</li>
<li>
deletes all log entries of category $category_name
wls_unregister( $category_name );
</li>
<li>
same as wls_clear & removes category $category_name from the list
wls_log( $category_name, $text, $user_id, $date, $blog_id, $severity = 0 );
</li>
<li>
inserts a new log entry into specified category
</li>
<li><code>$date</code> must be formated according to ISO 8601</li>
<li>
<code>$severity</code> should be one of defined severity levels (see above)
wls_simple_log( $log_name, $text, $severity = 0 );
</li>
<li>
equivalent to <code>wls_log( $category_name, $text, get_current_user_id(), date( 'c' ), get_current_blog_id(), $severity);</code>
</li>
</ul>

WordPress Logging Service

Provides a simple API for storing miscellaneous log entries and their overview in admin area.

Syed Balkhi

Jared Atchison

tripflex

Gregor Capuder

Wysija

No3x

SendLayer

MailPoet

WP Mail Logging is the most popular plugin for logging emails sent from your WordPress site. Simply activate it and it will work immediately, no extra configuration is needed.
<h3>Are your WordPress emails not being sent or delivered?</h3>
Use this plugin to log all outgoing emails from your WordPress site. If there are any errors when sending the email from your site, our email logs will catch that error and display it to you.
This will allow you to debug and fix your email sending issue.
<h3>Did a client not receive your email?</h3>
Our email logs allow you to resend any email that was sent from your site. No more lost emails!
<h3>Do you just want to keep a record of all emails sent from your site?</h3>
By default, WordPress and your web host do not log, store or keep track of emails sent from your website.
This plugin will allow you to do just that. Our email logs will store every email that is sent from your WordPress site.
You can search and view a particular email log, inspect its content or attachments, and even resend that email.
<h3>What email information is logged?</h3>
All emails sent from your WordPress site are logged. And here is the information that is stored:
<ul>
<li>Email Subject</li>
<li>Email Content (HTML or text)</li>
<li>Email Attachments</li>
<li>Email Headers (to, from, reply-to, cc, bcc, …)</li>
<li>Error Message (in case there was an error while attempting to send the email)</li>
<li>IP Address of originating server (can be enabled in the settings)</li>
<li>Date and Time of the email</li>
<li>Receiver (the TO email address)</li>
</ul>
<h3>Why are my logged emails still not delivered to the inbox?</h3>
There are a lot of steps that emails have to make in order to be delivered to the recipient’s inbox.
When your WordPress site sends an email, there’s no guarantee it will be delivered.
This is what the email’s journey looks like:
<ol>
<li>WordPress creates an email</li>
<li>WordPress passes the email to your website host and that email gets logged by our plugin</li>
<li>The host server takes the email and sends it (SMTP or Mail Transfer Agent)</li>
<li>Recipient server receives or blocks the email</li>
<li>If the email is accepted, the spam filter decides if it goes to the inbox or the spam folder</li>
<li>Recipients see the email and might open it.</li>
</ol>
This plugin does not track delivery after step 2.
If you have deliverability issues, we suggest installing the <a href="https://wordpress.org/plugins/wp-mail-smtp/" rel="ugc">WP Mail SMTP</a> plugin.
WP Mail SMTP fixes WordPress email deliverability problems, you can choose between 12 email providers (Gmail, Outlook, SendLayer, Mailgun, …) to resolve your email sending issue and it’s super easy to set up. WP Mail SMTP is trusted by more than 3 million websites.
<h3>Credits</h3>
The plugin was created and launched in 2014 by <a href="https://no3x.de/" rel="nofollow ugc">Christian Zöller</a>.

WP Mail Logging


Very easy to moving from local server to live site


moving from local server to live


Love this plugin!  Acts as a great debugging tool when outgoing SMTP is not working (seen often on VPS hosted instances without something like WP SMTP configured).  


Great debugging tool!


Nothing really more to write. I've been using the plugin for quite some time and haven't experienced any unexpected behavior.


Works seamlessly right after activation

Works well


Very useful seeing what should have gone out and figure out if there's something wrong with my mail server.


Helps keep my sanity


Sending email from WP can be problematic when the provider has a poor mailing service. This plugin is perfect to monitor the email activity, find possible problems, resend emails.



I'm using it simple and very complex sites. It's particularly useful to track emails sent by plugins (ecommerce, form managers and so on): most of the time, when there are problems, they can be solved looking at the log.



IMHO every site should have it.


A must have


Love this plugin. Save me from huge lose. 


Little but huge impact. Very helpfull

Log, view, and resend all emails sent from your WordPress site. Great for resolving email sending issues or keeping a copy for auditing.

WordPress Logging Service vs WP Mail Logging