Some of these features already exist, some are explained in the docs. 
Please ask for support on the lists if you need it, read the docs 
first, and if you have enhancement requests still, then create 
individual tickets for each issue.

1. when composing email, and after typing one or two letters, it is 
preferable that the Horde automatically expand all email addresses in 
address book that start with this one or these two letters, instead of 
typing the full address!

2. In inbox folder, we don't see attachment and forwarding symbol 
beside of each email (in case if the email contains an attachment or 
had been forwarded)! so it's better to show them

3. when being logged into Horde and if we are in inbox folder we don't 
see our own email address corresponding to this inbox, because some 
users usere than one email address in same time, so they open more 
than one window, so they don't know in which mailbox they are without   
checking the received emails of each address.

4. some users prefer to sort the received emails in their inbox not 
according to their date of arrival, neither to their subject or name 
or size, but they prefer to sort them according to "seen or unseen" 
messages, so they can keep unseen messages in the top even if they are 
older than some seen messages.

Thanks