Simple SMTP

Troubleshooting - PHPMailer.

The one instance where an SMTP error can be caused by this plugin is if the SMTP password is stored in the database when the secret keys have been regenerated. You will need to re-save the password to refresh the encryption keys.

You can always get assistance from your host and/or SMTP service provider.
Plugin compatibility
When using the logging functionality, the plugin will store the logged emails in the posts table, as an invisible post type. Normally this should work completely fine, but if you have a plugin that scans custom post types and sends an email about them, there's a chance the third-party plugin might get stuck in a loop. For plugins like this, it is best to disable the functionality on the logging post type (sbss_email_log).

The following plugins have had reported issues:
* Sucuri Security.
One or more of the settings are greyed out
This plugin supports being overridden by DEFINE, so please check to see that you are not setting a define for a WP Simple SMTP option. These are most commonly stored in the wp-config.php file.

The over-ride hierachy is as follows, with top being the most important.

Environmental variable.
Constant variable (wp-config define).
Multisite network settings.
Locally-configured settings.

How do I stop the logs from automatically purging?
The logs by default will auto-prune to avoid keeping sensitive details in logs and contributing to database bloat. But if you wish to keep the logs more permanently, then register the following hook (typically in your theme functions.php) to disable the auto-pruning functionality:

add_filter( 'simple_smtp_disable_log_prune', '__return_true' );

How is the SMTP password stored?
If openssl is available to PHP, then the password will be encrypted (not hashed) when stored in the database. If unavailable, the SMTP password will be saved into the database as plaintext. The more recommended way of storing the password is to define SMTP_PASS in your wp-config.php file, which should already be locked and inaccessible from the front-end.

Note: Multisite over-ride password is currently not encrypted. Please see this issue.
Can I change the amount of entries shown in the log view?
This can be adjusted by the 'simple_smtp_log_table_max_per_page' filter. Returning an integer value to this filter hook will adjust the table page limit.
Does this plugin support WordPress CLI?
Yes. With WP-CLI you can perform the following actions:

email-log View the log if enabled.
email-test Send a test email.

To view the available options and help documentation, run wp help or wp help <function name>.
Does this plugin work on WordPress Multisite?
Yes. Each site can have unique settings, unless overriding is on. The network will use the main site settings, so network admin emails will show up in the main site log.

Since version 1.2, network-activating the plugin grants special configuration options for super administrators. This includes the ability to set overrides and configure site admin access.
Why do I see capital texts next to the input boxes? (Debugging disabled input boxes)
To help diagnose disabled input boxes, when the WordPress site is in debugging mode, the input fields will show a small debug text to indicate where the setting came from.

CONFIG is the standard method of saving settings via the admin menu.
CONST are overrides typically set in either wp-config.php or your theme's functions.php.
MULTISITE are network-defined overrides set in the Network Mail panel.
ENV are pulled from the machine/server environmental settings.

One of the easiest aspects to contribute to is the SMTP quick configuration segment. If you wish to maintain this aspect, suggest a new setting, or report broken entries, see the SMTP quick config wiki page.