Breaking: #64668 - Content Element mailform moved to legacy extension

See forge#64668

Description

The fallback "mailform" functionality, containing the FORM ContentObject, the submission logic for sending mailform and the content element (CType=mailform) has been moved to the legacy extension "compatibility6". This mailform was available when the "Form" extension, introduced in TYPO3 CMS 4.7, was not installed.

The following options have been marked for deprecation:

$TYPO3_CONF_VARS][FE][secureFormmail]
$TYPO3_CONF_VARS][FE][strictFormmail]
$TYPO3_CONF_VARS][FE][formmailMaxAttachmentSize]

The following methods within TypoScriptFrontendController have been removed:

protected checkDataSubmission()
protected sendFormmail()
public extractRecipientCopy()
public codeString()
protected roundTripCryptString()

Impact

Mailform elements are missing and not rendered in the frontend anymore unless EXT:compatibility6 is loaded.

Affected installations

Any installation using the fallback "mailform" Content Element, the FrontendDataSubmissionController or the FORM Content Object directly will break. Additionally, any third party extension using the TypoScriptFrontendController methods directly will stop working with a fatal error.

Migration

For TYPO3 CMS 7, installing EXT:compatibility6 brings back the existing functionality. For the long term the affected installations should migrate to a different, better suited solution for sending mails and building forms.