Redmine

Environment:
  Redmine version                          2.3.1.stable.11845
  Ruby version                             1.9.2 (i486-linux)
  Rails version                            3.2.13
  Environment                              production
  Database adapter                         Mysql2

We send mail with only one string: "Freundliche Grüsse"

Original mail:

MIME-Version: 1.0
Received: by 10.114.38.229 with HTTP; Mon, 12 Aug 2013 20:56:04 -0700 (PDT)
Date: Tue, 13 Aug 2013 10:56:04 +0700
Delivered-To: ezhiryakov@mail.com
Message-ID: <CAN5rfSsXn675pMbiU1wqqfBpFromT05Y_xfF_XOgjXwKROen9g@mail.gmail.com>
Subject: Swipe screen [#38669]
From: Evgeny Zhiryakov <ezhiryakov@mail.com>
To: redmine <redmine@mail.com>
Content-Type: multipart/alternative; boundary=001a11c260fa53f8dc04e3cc380b

--001a11c260fa53f8dc04e3cc380b
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

Freundliche Gr=C3=BCsse

--001a11c260fa53f8dc04e3cc380b
Content-Type: text/html; charset=UTF-8
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr">Freundliche Gr=C3=BCsse<br></div>

--001a11c260fa53f8dc04e3cc380b--

When run task receive_imap we have error:

** Invoke redmine:email:receive_imap (first_time)
** Invoke environment (first_time)
** Execute environment
** Execute redmine:email:receive_imap
rake aborted!
invalid byte sequence in US-ASCII
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/core_extensions/string.rb:8:in `gsub'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/core_extensions/string.rb:8:in `to_lf'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/encodings/quoted_printable.rb:22:in `encode'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/body.rb:170:in `encoded'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/message.rb:1803:in `encoded'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/body.rb:153:in `block in encoded'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/parts_list.rb:11:in `block in collect'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/parts_list.rb:11:in `each'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/parts_list.rb:11:in `collect'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/body.rb:153:in `encoded'
/var/lib/gems/1.9.1/gems/mail-2.5.4/lib/mail/message.rb:1803:in `encoded'
/var/lib/gems/1.9.1/gems/actionmailer-3.2.13/lib/action_mailer/base.rb:434:in `set_payload_for_mail'
/var/lib/gems/1.9.1/gems/actionmailer-3.2.13/lib/action_mailer/base.rb:403:in `block in receive'
/var/lib/gems/1.9.1/gems/activesupport-3.2.13/lib/active_support/notifications.rb:123:in `block in instrument'
/var/lib/gems/1.9.1/gems/activesupport-3.2.13/lib/active_support/notifications/instrumenter.rb:20:in `instrument'
/var/lib/gems/1.9.1/gems/activesupport-3.2.13/lib/active_support/notifications.rb:123:in `instrument'
/var/lib/gems/1.9.1/gems/actionmailer-3.2.13/lib/action_mailer/base.rb:401:in `receive'
/home/redmine/redmine-2.3/app/models/mail_handler.rb:46:in `receive'
/home/redmine/redmine-2.3/lib/redmine/imap.rb:35:in `block in check'
/home/redmine/redmine-2.3/lib/redmine/imap.rb:32:in `each'
/home/redmine/redmine-2.3/lib/redmine/imap.rb:32:in `check'
/home/redmine/redmine-2.3/lib/tasks/email.rake:142:in `block (3 levels) in <top (required)>'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:246:in `call'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:246:in `block in execute'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:241:in `each'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:241:in `execute'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:184:in `block in invoke_with_call_chain'
/usr/lib/ruby/1.9.1/monitor.rb:201:in `mon_synchronize'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:177:in `invoke_with_call_chain'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/task.rb:170:in `invoke'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:143:in `invoke_task'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `block (2 levels) in top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `each'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:101:in `block in top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:110:in `run_with_threads'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:95:in `top_level'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:73:in `block in run'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:160:in `standard_exception_handling'
/var/lib/gems/1.9.1/gems/rake-10.0.4/lib/rake/application.rb:70:in `run'
/var/lib/gems/1.9.1/gems/rake-10.0.4/bin/rake:33:in `<top (required)>'
/usr/bin/rake:19:in `load'
/usr/bin/rake:19:in `<main>'
Tasks: TOP => redmine:email:receive_imap

What can we do with that?