Browsing German translation

467.

**None**: No anti-spam checks are performed on form submissions.

468.

**Simple**: Some basic checks are performed. Form submissions with email addresses that are not well-formed or that have an excessive number of URLs are rejected.

469.

**Advanced**: Performs additional checks to determine whether email addresses are real or contain URLs that are blacklisted. This requires an Internet connection.

470.

**Spamhaus URL deny list**: If set to 'Yes', URLs will be checked against the Spamhaus DNSBL. The `Spamhaus Project <https://www.spamhaus.org>`_ provides a URL blacklist that is free for non-commercial, low-traffic use. A professional use data feed service is also available but not supported in Mahara. Please read the `Spamhaus DNSBL usage terms <https://www.spamhaus.org/organization/dnsblusage.html>`_ before enabling this option.

471.

**SURBL URL deny list**: If set to 'Yes', URLs will be checked against the SURBL DNSBL. `SURBL <http://www.surbl.org>`_ provides a URL deny list that is free for organizations with fewer than 1,000 people. A professional use datafeed service is also available, but not supported in Mahara. Please read the `SURBL usage terms <http://www.surbl.org/usage-policy.html>`_ before enabling this option.

472.

**Disable external resources in HTML**: Turning this option on will prevent authors from embedding external resources such as images from remote sites into their forum posts and other HTML content. YouTube videos and other media can also not be embedded. It is however a good thing to do from a security standpoint since it does neutralise a few clever phishing attacks. See the `HTML Purifier documentation <http://htmlpurifier.org/live/configdoc/plain.html#URI.DisableExternalResources>`_ for more details.

473.

**reCAPTCHA on account registration / contact us forms**: If set to 'Yes', :index:`people who register themselves on the site <single: Security settings; reCAPTCHA>` and who use the 'Contact us' form when not logged in are required to fill in the `reCAPTCHA <https://www.google.com/recaptcha>`_ form. This is for spam protection.

474.

**reCAPTCHA site key**: Enter the site key for your site's reCAPTCHA account.

475.

**reCAPTCHA secret key**: Enter the secret key for your site's reCAPTCHA account.

476.

**HSTS override**: :index:`If <single: Security settings; HSTS override>` your web server already sets the HTTP Strict Transport Security (HSTS) header, then deactivate it here for Mahara. That prevents it from being set twice and causing an error when you check your site for the proper configuration, e.g. via an SSL check tool.