I installed Zimbra Open Source edition 7.1.3_GA_3346.UBUNTU10_64 UBUNTU10_64 FOSS in a test environment.
The problem is: When sending an e-mail from Microsoft Outlook in HTML format text with bold, italics, changing the font color, etc. to access the Zimbra WebMail account by e-mail is in text format with a file unknown text / rtf.
As a test I sent the e-mail to other accounts that I have (Gmail, Yahoo) and in their webmail e-mail appears correctly.
Someone is having the same problem and have managed to solve?
I've seen the link Issues with Microsoft Outlook RTF and Web Client which has a similar problem.
Thanks for your help and excuse my English.