The mail system works for me on the basis of Zimbra Release 6.0.7_GA_2473.F7_20100616200740 (FOSS). Approximately the following problem one month ago has come to light: a part of letters which get on POP3 the external client, are displayed not completely. That is the letter text is cut short or it is not visible attaches. Has checked up with following clients: Outlook, The Bat, Mozilla Thunderbird. At access through web handle these letters are visible completely.

How to me to troubleshoot?
I ask the help.