As it was mentioned above formit also uses phpmailer class (/core/model/modx/mail/phpmailer/class.phpmailer.php)
The problem was with $rt = @mail($to, $this->EncodeHeader($this->SecureHeader($this->Subject)), $body, $header, $params);
(line 482). With $params variable. I just removed it and got everything work)
$modx->mail->set(modMail::MAIL_SENDER, $sender);
I tried this idea first (blank &to field). While the error message went away I still did not get the mail. I updated phpmailer to version 5.1 and now it works (Evo comes with 1.73 go figure)]]>
for me the solution was only to leave blank &to=`` This parameter is not necessary if you write an e-mail address in Tool/configuration/User. [...]
<?php $message = "Test 1\r\nTest 2\r\nTest 3"; mail('[email protected]', 'Testing mail function', $message); echo $message; ?>