Hi Simon,

Try this patch. It fixes the issue for me.

Note how there is explicit logic to test whether the body conforms to the 7bit transfer encoding without having to be escaped.

We just remove that test.

Now, if the text encoding 7bit, and the charset is not ascii, then the transfer encoding becomes "quoted-printable" without trying to be clever and checking that the body is all in the 7 bit range.

Index: roundcube/program/lib/Mail/mime.php
===================================================================
--- roundcube.orig/program/lib/Mail/mime.php    2013-11-27 12:44:24.000000000 -0800
+++ roundcube/program/lib/Mail/mime.php 2013-11-27 12:47:42.000000000 -0800
@@ -1459,14 +1459,12 @@
         // text body
         if ($this->_build_params['text_encoding'] == '7bit'
             && !preg_match('/ascii/i', $this->_build_params['text_charset'])
-            && preg_match('/[^\x00-\x7F]/', $this->_txtbody)
         ) {
             $this->_build_params['text_encoding'] = 'quoted-printable';
         }
         // html body
         if ($this->_build_params['html_encoding'] == '7bit'
             && !preg_match('/ascii/i', $this->_build_params['html_charset'])
-            && preg_match('/[^\x00-\x7F]/', $this->_htmlbody)
         ) {
             $this->_build_params['html_encoding'] = 'quoted-printable';
         }

On 27.11.2013 06:26, Simon Loewenthal wrote:

On 2013-11-21 17:01, Michael Heydekamp wrote:

Am 21.11.2013 16:40, schrieb Michael Heydekamp:

That is not correct. If a message is qp-encoded, UTF-8 and 7bit can make perfect sense.

Sorry for sloppy phrasing, qp is by definition 7bit, of course.

But even if the message is NOT qp-encoded and does NOT contain any hi-bit characters, UTF-8 is still a correct declaration.

This still remains true. Cheers,

I thought I should follow up on this.  I changed RC settings to 
Composing Messages -> Compose Messages in HTML "only if forwarding or 
replying", and set Use MIMME encoding for 8 bit chars: unticked.

This message was sent with these settings, and the recipient could not 
read this on her iPad, and had the same error.  Unsure how to proceed 
here, and I wonder which part of the chain has caused  problems :  RC, 
postfix, dovecot, iPad ?


Return-Path: <test@example.co.uk>
Delivered-To: recipientTest@example.co.uk
Received: by example.co.uk (Postfix, from userid 33)
         id C502E95; Tue, 26 Nov 2013 18:20:41 +0100 (CET)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=example.co.uk; 
s=mail;
         t=1385486441; bh=my56qg4+ft888KqsjyLe3V88vUH5/k2dZyOhkwJSKOY=;
         h=To:Subject:Date:From;
         
b=e+JgFz/0H7cUX8FwwL3WcCyRt83cZwCcv0YTA7yPsOO++YXtUVZm+QXzp/yGNMt55
          
E0zl4u71q7LyhpSY/yXDCYc2I5LoqJvuXzvZMDZLRG7wGIo/kl21ABGYb4UCGYlJZz
          lUmOB9AaMVtVFQTjaO9gR333axEVVfaqI2UTwEU8=
To: recipientTest <recipientTest@example.co.uk>
Subject: Tell me if you can read the content, if you  =?UTF-8?Q?can=3F?=
X-PHP-Originating-Script: 501:rcmail.php
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8;
  format=flowed
Content-Transfer-Encoding: 7bit
Date: Tue, 26 Nov 2013 18:20:41 +0100
 From: Test Test <test@example.co.uk>
Message-ID: <f8edfd355dafb0698e108c11e91b44cf@example.co.uk>
X-Sender: test@example.co.uk
User-Agent: Roundcube Webmail/0.9.5

Tell me if you can read this, if you can?