sorry my english not good..!

I have setup and try zimbra at this week,and I have tried Scalix Communtnity Edition month ago, but I dont want Sendmail as MTA server at scalix CE, and I look zimbra good better prospect for future...

and I have more question for zimbra

1. I dont want used clear text password ..and when I used External mail
Client ( thunder bird, etc.. ) but autentification is Reject ..??

2. when I want send email use collaboration suite / webmail , I Cannot look
up LDAP address book on server..?

3. and when I used External mail Client and lookup address book via LDAP
server zimbra, and do not display name ( First and Last name ) account
name only.?
4. why Distribution List ( Group mail ) there is not Display name?

4. When Zimbra full release is launching ..?