Title: Duplicate Mime Version Headers Last modified: March 2, 2019 --- # Duplicate Mime Version Headers * Resolved [ollybach](https://wordpress.org/support/users/ollybach/) * (@ollybach) * [7 years, 3 months ago](https://wordpress.org/support/topic/duplicate-mime-version-headers/) * It seems the plugin indiscriminately sets a second mime version header even if it already exists. for many servers this might be fine, but for some it is not and then throw errors like so `SMTP Error: data not accepted.SMTP server error: DATA END command failed Detail: Transaction failed: Duplicate header 'MIME-Version'.` * i.e, i simply (programatically) send the following email – the variables are of course replaced with whats appropriate – a second Mime-Version header gets added by WP Mail SMTP * ``` $headers = array(); $headers['mime'] = "MIME-Version: 1.0"; $headers['content'] = "Content-type: ".$mail_message['type']."; charset=".$mail_message['charset'].""; $headers['from'] = "From: ".$from_name." <".$from_address.">"; $headers['mailer'] = "X-Mailer: PHP/".phpversion(); /* implode */ $headers = implode("\r\n", $headers); /* send the email */ $sending_mail = wp_mail($recipient, $subject, $message, $headers); ``` * any advise ? Viewing 6 replies - 1 through 6 (of 6 total) * Plugin Author [Slava Abakumov](https://wordpress.org/support/users/slaffik/) * (@slaffik) * [7 years, 3 months ago](https://wordpress.org/support/topic/duplicate-mime-version-headers/#post-11276580) * Hi * Could you please provide a complete original email with all of its headers (including doubled `MIME-Version`)? * Thread Starter [ollybach](https://wordpress.org/support/users/ollybach/) * (@ollybach) * [7 years, 3 months ago](https://wordpress.org/support/topic/duplicate-mime-version-headers/#post-11276872) * there you go (i’ve removed/changed real email addresses/domain/ipaddresses for dummy ones though) * ``` From - Tue Mar 5 14:13:17 2019 X-Account-Key: account1 X-UIDL: UID46479-1442527387 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 X-Mozilla-Keys: Return-Path: Delivered-To: my-mail@domain.com Received: from dns.domain.com by dns.domain.com with LMTP id XXXXXXXXXXXXXXXXXX/7Q (envelope-from ) for ; Tue, 05 Mar 2019 14:12:16 +0000 Return-path: Envelope-to: my-mail@domain.com Delivery-date: Tue, 05 Mar 2019 14:12:16 +0000 Received: from 00-000-00-00.xxx.xxxxx.xxxxx.xx ([00.000.00.00]:59584 helo=www.domain.com) by dns.domain.com with esmtps (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.91) (envelope-from ) id 1h1Ann-000000-UJ for my-mail@domain.com; Tue, 05 Mar 2019 14:12:16 +0000 Date: Tue, 5 Mar 2019 14:12:16 +0000 To: my-mail@domain.com From: test Subject: some subject line. Message-ID: X-Mailer: WPMailSMTP/Mailer/smtp 1.4.1 MIME-Version: 1.0 X-Mailer: PHP/7.3.1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit some plaintext content here ``` * Plugin Author [Slava Abakumov](https://wordpress.org/support/users/slaffik/) * (@slaffik) * [7 years, 3 months ago](https://wordpress.org/support/topic/duplicate-mime-version-headers/#post-11281303) * Do all emails have a similar header? Including the test email that you can send on “Email Test” tab in the plugin admin area? * Thread Starter [ollybach](https://wordpress.org/support/users/ollybach/) * (@ollybach) * [7 years, 3 months ago](https://wordpress.org/support/topic/duplicate-mime-version-headers/#post-11281671) * In fact – after a bit more digging around my end – this does not actually seem to be caused by WP Mail SMTP after all (what i was referring to are emails that are being sent in a loop by wp_cron) * Not sure yet why this happens as I have used wp_mail many times before without ever having this issue. So, let’s consider this resolved I would say (I can always get back to you if it turns out there’s some strange interaction going on between things) * Thanks for the support nevertheless (your suggestions also helped me to narrow things down somewhat) . Sorry for wasting your time * Plugin Author [Slava Abakumov](https://wordpress.org/support/users/slaffik/) * (@slaffik) * [7 years, 3 months ago](https://wordpress.org/support/topic/duplicate-mime-version-headers/#post-11282720) * [@ollybach](https://wordpress.org/support/users/ollybach/) * Yeah, I was wondering too how the plugin can cause that as it just converts all the headers and adds only 1 (`X-Mailer`). It’s not wasting, it’s investigation 🙂 * Get back to me if you understand the issue or WP Mail SMTP is in charge of that. * Thanks! * Thread Starter [ollybach](https://wordpress.org/support/users/ollybach/) * (@ollybach) * [7 years, 3 months ago](https://wordpress.org/support/topic/duplicate-mime-version-headers/#post-11282780) * cheers, * FYI: as it turns out is is the Worderpress phpmailer class that adds the additional` MIME-Version: 1.0` to the emails , regardless of whether it was set already. It also *appears* (not checked for all eventualities though) that this only happens when using `wp_cron` to send these mails and only if using `wp_mail`. * if i use `mail` instead, this does not happen (or one would think if using `wp_mail` but not setting that Mime header in the first place as phpmailer adds it anyway) * there are in fact also some google results regarding WP and duplicate mime-version headers, though nothing that specifically refers to wp_cron as such, but I have not extensively read through all those trac tickets either admittedly as I found a solution for my specific scenario, but maybe the above info will help someone one day * again, thanks for your time Viewing 6 replies - 1 through 6 (of 6 total) The topic ‘Duplicate Mime Version Headers’ is closed to new replies. * ![](https://ps.w.org/wp-mail-smtp/assets/icon-256x256.png?rev=1755440) * [WP Mail SMTP by WPForms - The Most Popular SMTP and Email Log Plugin](https://wordpress.org/plugins/wp-mail-smtp/) * [Frequently Asked Questions](https://wordpress.org/plugins/wp-mail-smtp/#faq) * [Support Threads](https://wordpress.org/support/plugin/wp-mail-smtp/) * [Active Topics](https://wordpress.org/support/plugin/wp-mail-smtp/active/) * [Unresolved Topics](https://wordpress.org/support/plugin/wp-mail-smtp/unresolved/) * [Reviews](https://wordpress.org/support/plugin/wp-mail-smtp/reviews/) * 6 replies * 2 participants * Last reply from: [ollybach](https://wordpress.org/support/users/ollybach/) * Last activity: [7 years, 3 months ago](https://wordpress.org/support/topic/duplicate-mime-version-headers/#post-11282780) * Status: resolved