Use tinymce from tinycme package instead of the shipped one.
-Index: roundcube-0.1~rc2/program/steps/mail/sendmail.inc
+Index: b/program/steps/mail/sendmail.inc
===================================================================
---- a/program/steps/mail/sendmail.inc~ 2008-04-30 10:21:42.000000000 +0200
-+++ a/program/steps/mail/sendmail.inc 2008-06-22 13:51:33.000000000 +0200
-@@ -74,7 +74,7 @@
-
- $last_img_pos = 0;
+--- a/program/steps/mail/sendmail.inc 2009-10-14 12:52:27.000000000 +0200
++++ b/program/steps/mail/sendmail.inc 2010-07-17 17:33:23.000000000 +0200
+@@ -115,7 +115,7 @@
-- $searchstr = 'program/js/tiny_mce/plugins/emotions/images/';
-+ $searchstr = 'program/js/tiny_mce/plugins/emotions/img/';
+ // sanitize image name so resulting attachment doesn't leave images dir
+ $image_name = preg_replace('/[^a-zA-Z0-9_\.\-]/i', '', $image_name);
+- $img_file = INSTALL_PATH . '/' . $searchstr . $image_name;
++ $img_file = '/usr/share/tinymce/www/plugins/emotions/img/' . $image_name;
- // keep track of added images, so they're only added once
- $included_images = array();
---- roundcube-0.1~rc2.orig/program/steps/mail/sendmail.inc 2007-11-26 11:42:36.000000000 +0100
-+++ roundcube-0.1~rc2/program/steps/mail/sendmail.inc 2007-11-26 11:44:04.000000000 +0100
-@@ -108,7 +108,7 @@
- if (! in_array($image_name, $included_images))
- {
- // add the image to the MIME message
-- $img_file = INSTALL_PATH . '/' . $searchstr . $image_name;
-+ $img_file = '/usr/share/tinymce/www/plugins/emotions/img/' . $image_name;
-- if(! $mime_message->addHTMLImage($img_file, 'image/gif', '', true, '_' . $image_name))
-+ if(! $mime_message->addHTMLImage($img_file, 'image/gif', '', true, $image_name))
- $OUTPUT->show_message("emoticonerror", 'error');
-
---- a/program/steps/mail/sendmail.inc~ 2008-04-30 10:21:42.000000000 +0200
-+++ a/program/steps/mail/sendmail.inc 2008-06-22 14:10:24.000000000 +0200
-@@ -102,7 +102,7 @@
- array_push($included_images, $image_name);
- }
-
-- $body = $body_pre . 'cid:_' . $image_name . $body_post;
-+ $body = $body_pre . $img_file . $body_post;
-
- $last_img_pos = $pos2;
- }
+ if (! in_array($image_name, $included_images)) {
+ // add the image to the MIME message