Event "SendMailServicePrepareAndSendEvent": Not possible to change message object as stated in documentation

[tntrpsw]

In the powermail documentation the event "SendMailServicePrepareAndSendEvent" ist described as

Change the message object before sending

But trying to use this event in order to change the email's subject seems not to be possible.

After taking a look in the powermail sources, it seems that no data from the event object other than "isAllowedToSend()" ist evaluated or used for the actual sending of the email. So using this event to (as advertised) "Change the message object before sending" is not possible.

So, would it be possible to change powermail's prepareAndSend() function to create the advertised functionality? Maybe my adding a

$message = $event->getMailMessage();
$email = $event->getEmail();

just before calling $message->send(); ?

TYPO3 12.4.26 (legacy; no composer)
powermail 12.5.1

powermail's event description:
Location:In2code\Powermail\Domain\Service\Mail\SendMailService::prepareAndSend()
Event: In2code\Powermail\Events\SendMailServicePrepareAndSendEvent
escription: Change the message object before sending

[twestner]

Hi,

I can confirm this issue - changed things do not get back from SendMailServicePrepareAndSendEvent to SendMailService yet. And I also can confirm the solution by adding this two lines.

Powermail 12.5.3
TYPO3 12.4.34

Attached you find my patch for V12, perhaps it also works for V13. I have not checked yet. Maybe it helps.

powermail.issue1236.patch