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Large number of mail delivery failures "Body type not supported by remote host"

  • 14 replies
  • 57 have this problem
  • 94 views
  • Last reply by Lange99

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I recently upgraded to version 45.0 of Thunderbird, and since then a number of mails are returned as delivery failed. Message: Action: failed Status: 5.6.1 Diagnostic-Code: smtp;554 5.6.1 Body type not supported by Remote Host

I have never had this problem before (sending mail to same recipients now failing). I have tried both plain text and HTML, both are rejected. Some emails do get through, but there is no difference is settings to those rejected. Happens both to email addresses in address book, and those not in address book.

I have found the same problem on various forums, but solutions are not specific for Thunderbird, or do not work.

Any suggestions?

I recently upgraded to version 45.0 of Thunderbird, and since then a number of mails are returned as delivery failed. Message: Action: failed Status: 5.6.1 Diagnostic-Code: smtp;554 5.6.1 Body type not supported by Remote Host I have never had this problem before (sending mail to same recipients now failing). I have tried both plain text and HTML, both are rejected. Some emails do get through, but there is no difference is settings to those rejected. Happens both to email addresses in address book, and those not in address book. I have found the same problem on various forums, but solutions are not specific for Thunderbird, or do not work. Any suggestions?

Chosen solution

Based on a suggestion I found with google, I went in the config editor and changed the line "mail.strictly_mime" from false to true. This seems to work and mail in now getting through. My only concern is that:

  • I do not fully understand what this change actually implies (i.e. can I now expect problems with other mails), and
  • why it suddenly occurs after years of use of Thunderbird. I assume either a change in release 45.0, or a recent patch to Microsoft servers.
Read this answer in context 👍 7

All Replies (14)

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Is that the entire error message? Is the error message from your provider's server or from the recipients provider server?

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This is the full message

===============================================

This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed.

      admin@xxxxxxxxxx (correct address, changed for privacy reasons)


Reporting-MTA: dns;cpsmtpb-ews03.kpnxchange.com Received-From-MTA: dns;cpsps-ews03.kpnxchange.com Arrival-Date: Fri, 22 Apr 2016 17:51:49 +0200

Final-Recipient: xxxxxxxxxxxxxxxxxx Action: failed Status: 5.6.1 Diagnostic-Code: smtp;554 5.6.1 Body type not supported by Remote Host

===============================================

The error message is from my provider's server. Stating that the recipient's server would not accept the message. In this case, the mail was sent to two recipients, the other on gmail. The gmail one was accepted.

Modified by Mark-E-H

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So then either you or the recipient should contact the recipients email provider.

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This problem started this week, with several recipients, but not all. It is not just one, but several completely different ones. I know that for some recipients nothing changed on their provider's side. For other I do not know. I do not understand why an email is rejected now, but was accepted in the past.

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I could probably think a more than a dozen changes that neither you of the recipient would normally be aware of that could cause issues. But here are some very common ones.

The recipient as has received a patch for exchange server (monthly) The server admin has chaged security levels on the server The server admin has created a new rule for accepting mail (they don't have to take everything that arrives) Their anti virus suite is updated (Daily) The mail system has has an Anti SPAM spam front end installed or updates Their mail host/Internet Host have changes their firewall settings.


What is clear from the MTS name is that it is probably Microsoft Exchange Server your connecting to. So Google hits mentioning that product will be more likely to contain useful information.

Given what I have read on Google this morning I would think that character encoding might be an issue. especially with attachments.

On the toolbar > Options > Display > Formatting > advanced and set your character encoding to UTF-8) and tick the When possible box at the bottom.

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Thank you. This is the type of info I was looking for, but unfortunately it did not do the trick. I already had the UTF-8 setting, but had not checked the box. Changed that. I have tried one failed recipient again and the email still fails:

===========================================================

This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed.

      info@broedersinch......


Reporting-MTA: dns;cpsmtpb-ews02.kpnxchange.com Received-From-MTA: dns;cpsps-ews27.kpnxchange.com Arrival-Date: Sun, 24 Apr 2016 07:15:17 +0200

Final-Recipient: rfc822;info@broedersinch...... Action: failed Status: 5.6.1 Diagnostic-Code: smtp;554 5.6.1 Body type not supported by Remote Host

===========================================================

It happens in both original mails and replies to specific email addresses. These mails did not have attachments.

Modified by Mark-E-H

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Admin, Info.... those are the sorts of addresses that admins routinely restrict to plain text, no attachments. So have you tried plain text no attachments.

Can you send to a "normal" user email address on those domains?

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With a "normal user" I get the same problem.

Reporting-MTA: dns;cpsmtpb-ews01.kpnxchange.com Received-From-MTA: dns;cpsps-ews30.kpnxchange.com Arrival-Date: Sun, 24 Apr 2016 14:05:57 +0200

Final-Recipient: rfc822;nel.dav...@broedersinch...... Action: failed Status: 5.6.1 Diagnostic-Code: smtp;554 5.6.1 Body type not supported by Remote Host

All failed mails have been without attachments. I have tried plain text and HTML. Makes no difference. I am trying very simple mails: just a title and one line of text. Occurs both with new mail and with replies.

But all mails which failed have been addresses of companies / institutions / etc., and not generic mail servers such as gmail. Web-mail (in Firefox) is accepted by these recipients without problems. Only mail sent with Thunderbird is failing. I am looking for a way to be able to send mails to these recipients without having to resort to web-mail.

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Chosen Solution

Based on a suggestion I found with google, I went in the config editor and changed the line "mail.strictly_mime" from false to true. This seems to work and mail in now getting through. My only concern is that:

  • I do not fully understand what this change actually implies (i.e. can I now expect problems with other mails), and
  • why it suddenly occurs after years of use of Thunderbird. I assume either a change in release 45.0, or a recent patch to Microsoft servers.
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Where did you find this suggestion with google? i have a similar glitch sending to one aol email address.

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teegeepen said

Where did you find this suggestion with google? i have a similar glitch sending to one aol email address.

http://forums.mozillazine.org/viewtopic.php?t=1730465

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Hi Mark,

Did this solution work for you ? I have the same problem. I tried using web-mail and was able to get through. But that solution is not very practical. So I assume the problem is within Thunderbird. I am also using version 45.2.0, downloaded and installed some time mid May. And had the problem for the first time around mid June. Most emails get through without problems. The @dresses affected are those with firstname@lastname.com kind of format and CompuServe (cs.com). Success and regards - lange99

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Yes, the solution with a change in the config works for me. The problem has not returned, all mails are sent (and arrive).

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Well done. Good for you ...... I hope - and trust - our moderator will have seen these posts and that these changes to the config will be part of (one of) the next version(s) of Thunderbird ....... I think I will wait for the update. I am somewhat hesitant to start editing the config. We'll see ..... Best regards to all !!