Action Mailer Errno::EPIPE using different character sets

  1. On my Windows development system everything is fine.
  2. On my Linux production server I get an Errno::EPIPE (Broken pipe)
    error when sending an email using Action Mailer. The specific situation
    is this:
    a) Rails 1.1.2
    b) The application is running UTF8, but I want to send my emails as
    ISO-8859-1.
    c) Sending UTF-8 emails works fine.
    d) Delivery method is SMTP.
    e) When using this code

def confirm(uuid, user, shop)
	@subject		= "Shop-Anmeldung bei uns"
	@body['uuid'] = uuid
	@body['user'] = user
	@body['shop'] = shop
	@recipients = user.name
	@bcc = '[email protected]'
	@from = '[email protected]'
	@sent_on = Time.now
	@headers = {}
	@charset    = "iso-8859-1"
end

and including German Umlauts (äöü etc.) in the template (saved as
ISO8859-1) I get the above error. As soon as I change my template to not
include any Umlauts all works fine. It seems that my @charset setting is
ignored.
3. The top portion of the call stack looks like this:
usr/local/lib/ruby/1.8/net/protocol.rb:266:in write' /usr/local/lib/ruby/1.8/net/protocol.rb:266:inwrite0’
/usr/local/lib/ruby/1.8/net/protocol.rb:280:in write_message_0' /usr/local/lib/ruby/1.8/net/protocol.rb:277:ineach_crlf_line’
/usr/local/lib/ruby/1.8/net/protocol.rb:311:in adding' /usr/local/lib/ruby/1.8/net/protocol.rb:335:instep’
/usr/local/lib/ruby/1.8/net/protocol.rb:335:in adding' /usr/local/lib/ruby/1.8/net/protocol.rb:311:ineach_crlf_line’
/usr/local/lib/ruby/1.8/net/protocol.rb:277:in write_message_0' /usr/local/lib/ruby/1.8/net/protocol.rb:229:inwrite_message’
/usr/local/lib/ruby/1.8/net/protocol.rb:228:in using_each_crlf_line' /usr/local/lib/ruby/1.8/net/protocol.rb:290:inwriting’
/usr/local/lib/ruby/1.8/net/protocol.rb:290:in using_each_crlf_line' /usr/local/lib/ruby/1.8/net/protocol.rb:228:inwrite_message’
/usr/local/lib/ruby/1.8/net/smtp.rb:473:in sendmail' /usr/local/lib/ruby/1.8/net/smtp.rb:472:insend0’
/usr/local/lib/ruby/1.8/net/smtp.rb:548:in critical' /usr/local/lib/ruby/1.8/net/smtp.rb:548:insend0’
/usr/local/lib/ruby/1.8/net/smtp.rb:472:in sendmail' /usr/local/lib/ruby/gems/1.8/gems/actionmailer-1.2.1/lib/action_mailer/base.rb:449:inperform_delivery_smtp’
/usr/local/lib/ruby/gems/1.8/gems/actionmailer-1.2.1/lib/action_mailer/base.rb:447:in
start' /usr/local/lib/ruby/1.8/net/smtp.rb:316:instart’
/usr/local/lib/ruby/gems/1.8/gems/actionmailer-1.2.1/lib/action_mailer/base.rb:447:in
perform_delivery_smtp' /usr/local/lib/ruby/gems/1.8/gems/actionmailer-1.2.1/lib/action_mailer/base.rb:333:insend’
/usr/local/lib/ruby/gems/1.8/gems/actionmailer-1.2.1/lib/action_mailer/base.rb:333:in
deliver!' /usr/local/lib/ruby/gems/1.8/gems/actionmailer-1.2.1/lib/action_mailer/base.rb:258:indeliver’

Is what I am doing totally stupid? Am I missing any config settings. Any
help would be much appreciated.