Mail Deprecation Bug after Typo3 Update to 4.5

After updating Typo3 4.3, 4.4 to Typo3 4.5 I received some Deprecation Warnings: Validation failed for: …
Also I had had one project where the mail text was krypted.

Following typo3conf/localconf.php entry fixed this:

$TYPO3_CONF_VARS['MAIL']['substituteOldMailAPI'] = '0';