Added default values to raise_delivery_errors guide (#45616)

guides/source/action_mailer_basics.md

@@ -814,7 +814,7 @@ files (environment.rb, production.rb, etc...)
 |`logger`|Generates information on the mailing run if available. Can be set to `nil` for no logging. Compatible with both Ruby's own `Logger` and `Log4r` loggers.|
 |`smtp_settings`|Allows detailed configuration for `:smtp` delivery method:<ul><li>`:address` - Allows you to use a remote mail server. Just change it from its default `"localhost"` setting.</li><li>`:port` - On the off chance that your mail server doesn't run on port 25, you can change it.</li><li>`:domain` - If you need to specify a HELO domain, you can do it here.</li><li>`:user_name` - If your mail server requires authentication, set the username in this setting.</li><li>`:password` - If your mail server requires authentication, set the password in this setting.</li><li>`:authentication` - If your mail server requires authentication, you need to specify the authentication type here. This is a symbol and one of `:plain` (will send the password in the clear), `:login` (will send password Base64 encoded) or `:cram_md5` (combines a Challenge/Response mechanism to exchange information and a cryptographic Message Digest 5 algorithm to hash important information)</li><li>`:enable_starttls` - Use STARTTLS when connecting to your SMTP server and fail if unsupported. Defaults to `false`.</li><li>`:enable_starttls_auto` - Detects if STARTTLS is enabled in your SMTP server and starts to use it. Defaults to `true`.</li><li>`:openssl_verify_mode` - When using TLS, you can set how OpenSSL checks the certificate. This is really useful if you need to validate a self-signed and/or a wildcard certificate. You can use the name of an OpenSSL verify constant ('none' or 'peer') or directly the constant (`OpenSSL::SSL::VERIFY_NONE` or `OpenSSL::SSL::VERIFY_PEER`).</li><li>`:ssl/:tls` - Enables the SMTP connection to use SMTP/TLS (SMTPS: SMTP over direct TLS connection)</li><li>`:open_timeout` - Number of seconds to wait while attempting to open a connection.</li><li>`:read_timeout` - Number of seconds to wait until timing-out a read(2) call.</li></ul>|
 |`sendmail_settings`|Allows you to override options for the `:sendmail` delivery method.<ul><li>`:location` - The location of the sendmail executable. Defaults to `/usr/sbin/sendmail`.</li><li>`:arguments` - The command line arguments to be passed to sendmail. Defaults to `-i`.</li></ul>|
-|`raise_delivery_errors`|Whether or not errors should be raised if the email fails to be delivered. This only works if the external email server is configured for immediate delivery.|
+|`raise_delivery_errors`|Whether or not errors should be raised if the email fails to be delivered. This only works if the external email server is configured for immediate delivery. Defaults to `true`.|
 |`delivery_method`|Defines a delivery method. Possible values are:<ul><li>`:smtp` (default), can be configured by using [`config.action_mailer.smtp_settings`][].</li><li>`:sendmail`, can be configured by using [`config.action_mailer.sendmail_settings`][].</li><li>`:file`: save emails to files; can be configured by using `config.action_mailer.file_settings`.</li><li>`:test`: save emails to `ActionMailer::Base.deliveries` array.</li></ul>See [API docs](https://api.rubyonrails.org/classes/ActionMailer/Base.html) for more info.|
 |`perform_deliveries`|Determines whether deliveries are actually carried out when the `deliver` method is invoked on the Mail message. By default they are, but this can be turned off to help functional testing. If this value is `false`, `deliveries` array will not be populated even if `delivery_method` is `:test`.|
 |`deliveries`|Keeps an array of all the emails sent out through the Action Mailer with delivery_method :test. Most useful for unit and functional testing.|