Issue with mailSend function in PHPMailer.php

[chadquilter]

Hello, If I am missing anything apologies (maybe this is wordpress issue not adjusting to PHPMailer) but it looks like there might be an issue with a condition in the mailSend function on line 1864 (or there about's). The first condition to set the Sender attribute:

    if ('' === $this->Sender) {
        $this->Sender = $this->From;
    }

Will not trigger the below checks to add the "-f" flag to the start of the sender string, which will cause the mailer to fail should your MTA require a valid from sender. (copied logic below for context)...in fact it looks like the below will never run if Sender is empty and From is defined never adding the -f option.

    if (empty($this->Sender) && !empty(ini_get('sendmail_from'))) {
        //PHP config has a sender address we can use
        $this->Sender = ini_get('sendmail_from');
    }

    if (!empty($this->Sender) && static::validateAddress($this->Sender)) {
        if (self::isShellSafe($this->Sender)) {
            $params = sprintf('-f%s', $this->Sender);
        }
        $old_from = ini_get('sendmail_from');
        ini_set('sendmail_from', $this->Sender);
    }

Thanks, sorry again if I am missing something.

[Synchro]

Are you referring to #2298? Most of that code is gone now.

[chadquilter]

Yea, this was exactly my issue. Many thanks! I should have done a search in closed bugs!