This issue relates to JRA-5238. When replying to the html version of jira emails from outlook, outlook adds a ruled line between messages. Below is the code that I currently use to test for the different outlook reply email formats (using java 1.4's regex matching).

private static final Pattern OUTLOOK_HTML_COMMENT = Pattern.compile("\\s\\r\\n+_

\\s\\r\\n+From:.*", Pattern.DOTALL);
private static final Pattern OUTLOOK_TEXT_COMMENT = Pattern.compile("\\s\\r\\n
s+(Original Message|Ursprüngliche Nachricht|Original Message Follows)
s++\\r\\n+From:.*", Pattern.DOTALL);

....

public String stripQuotedLines(String body)
{
....
String nonQuotedMsg = result.toString();
Matcher matcher = OUTLOOK_HTML_COMMENT.matcher(nonQuotedMsg);
if (matcher.find()) nonQuotedMsg = matcher.replaceFirst("");

matcher = OUTLOOK_TEXT_COMMENT.matcher(nonQuotedMsg);
if (matcher.find()) nonQuotedMsg = matcher.replaceFirst("");
return nonQuotedMsg;
}

In fact, IMHO, the entire code of the stripQuotedLines() method could very easily be refactored using a few regular expressions - it would make the code much tighter.