TYPO3 Core

Although htmlmail is marked as deprecated htmlmail is still used in many extensions, e.g. sr_feuser_register. Therefore, this error should be fixed unless htmlmail is removed soon.

In my opinion, a correct fix would be:

$this->add_header('From: "' . addslashes($this->from_name) . '" <' . $this->from_email . '>');

The problem is that if you enable the use of swiftmailer through htmlmail the "From" line is checked by swiftmailer and if e.g. a "." appears in the from_name an exception is thrown!

fixed by moving to swiftmailer