plesk-sendmail[3207]: S3207: Unable to prepare arguments for mail handlers.

When using this Plugin to Monitor Plesk Mailserver it throws this Error: plesk-sendmail[3207]: S3207: Unable to prepare arguments for mail handlers.

The cause of the problem is the absence of a new line between the email header and the content in the mails

Previously, OS Sendmail was used instead of Plesk Sendmail when that happened. Therefore, functions such as DKIM did not work. No error message about the problem was printed in the maillog.

In version 18.0.38 of Plesk, such a phenomenon is now recognized as an error. Therefore, before the OS sendmail is executed, Plesk will output an error message and stop sending mail.

To fix the problem I can suggest that you enter a new line between the email header and the content in your website code.

Example (send_mail_ver2):

$ fp = popen ($ new_send_mail_command. "-F". $ Sender_from_addr, "w");
fputs ($ fp, $ subject);
fputs ($ fp, "\ n");
fputs ($ fp, "MIME-Version: 1.0 \ n");
fputs ($ fp, "From:". $ From_addr. "\ N");
fputs ($ fp, "To:". $ To_addr. "\ N");
fputs ($ fp, "Reply-to:". $ Reply_to. "\ n");
fputs ($ fp, "Content-Type: text / plain; charset = \" ISO-2022-jp \ "\ n");
fputs ($ fp, "Content-Transfer-Encoding: base64 \ n");
fputs ($ fp, "X-Mailer: Mailer \ n");
fputs ($ fp, "\ n"); // Add this line.
fputs ($ fp, base64_encode ($ content). "\ n");

setec / check-email-loop

plesk-sendmail[3207]: S3207: Unable to prepare arguments for mail handlers. #5