Sorry for no feedback, i have been too busy...

Renaming the IMAP Sent folder from "Sent Items" to "Sent" works around 
this issue in Imp.

Imp accepts and uses the Sent folder without creating additional 
folders, which it persists in doing for Sent folders named other than 
Sent (even when selected as the Sent folder in Personal preferences).

Ping?

I'll do some digging.

Initial look using Chrome dev tools in my Horde account, starting a 
New Message in Imp shows the new message page that refers to "Tick / 
Save in {Sent}" with a mailbox ID that refers to the correct Cyrus 
IMAP Sent Items folder.

Using that mailbox ID in the URL drops me into the Imp tree's Sent 
folder, which I'd expect, as it all works fine from my account.

One interesting thing is that Imp refers to my Cyrus IMAP "Sent Items" 
folder within the Imp tree folder structure as "Sent" not "Sent Items" 
(just as it masks my "Deleted Items" folder and calls it "Trash"), and 
that Sent name is what reflects into the New Message page.

I'll check what references my wife's New Message page comes up with 
when I select Sent Items in the drop down on hers, that causes the 
generation of the surplus "Sent" folder, and post back.

Can't reproduce.  You will need to trace the javascript code yourself 
to see why it is not updating correctly.



For further debugging information, please read 
http://www.horde.org/apps/horde/docs/INSTALL#dynamic-view-troubleshooting

Any progress on this one?

My account has the following a the end of pref - horde - identities entry
    in SQL:

"save_sent_mail";i:1;s:16:"sent_mail_folder";s:10:"Sent Items";}}

In my Imp Personal Information page, "Save Sent mail?" is checked, and
    "Sent mail mailbox" is "Sent Items".

When I start a "new message", at the top of the webpage it has "tick / Save
    in 'Sent'" (not Sent Items), yet when I select the drop down arrow, the
    correct folder Sent Items is selected. Sent mail is being correctly saved
    into "Sent Items".

New user has:

"save_sent_mail";i:1;s:16:"sent_mail_folder";s:10:"Sent Items";}}

in her SQL pref. In Imp Personal Information page, "Save Sent mail?" is
    checked, and "Sent mail mailbox" is "Sent Items".

Yet when she opens "New Message", she is notified "The mailbox "Sent" was
    successfully created". At the top of the new massage page, "tick / Save in
    'Sent Items'" is displayed, and when I select the drop down arrow, the
    correct folder Sent Items is selected. Sent mail is being correctly saved
    into "Sent Items".

I end up though with a "Sent" folder that I cannot ever get rid of...
    not used by anything, but recreated if deleted by the "New Message"
    process.

So I have two questions:

1. Why does my New Message say 'Sent' yet maps to 'Sent Items'?
    2. Why does the other user's mail insist on creating a 'Sent' folder
    when it's never used?


$conf[server][fixed_folders]  is set to Drafts, Sent Items, Spam, Deleted
    Items

In case I have broken something with prefs:

Imp's prefs.local.php is:

$_prefs['atc_flag']['value'] = '1';
    $_prefs['compose_html']['value'] = '1';
    $_prefs['delete_attachments_monthly_keep']['value'] = '0';
    $_prefs['delete_spam_after_report']['value'] = '2';
    $_prefs['emoticons']['value'] = '1';
    $_prefs['empty_spam_menu']['value'] = '1';
    $_prefs['empty_trash_menu']['value'] = '1';
    $_prefs['filter_menuitem']['value'] = '1';
    $_prefs['initial_page']['value'] = 'INBOX';
    $_prefs['mailbox_return']['value'] = '1';
    $_prefs['mailbox_start']['value'] = '3';
    $_prefs['mail_domain']['value'] = 'simonandkate.net';
    $_prefs['move_innocent_after_report']['value'] = '1';
    $_prefs['nav_expanded']['value'] = '0';
    $_prefs['purge_spam_interval']['value'] = '3';
    $_prefs['purge_trash_interval']['value'] = '2';
    $_prefs['refresh_time']['value'] = '900';
    $_prefs['reply_format']['value'] = '1';
    $_prefs['reply_headers']['value'] = '1';
    $_prefs['request_mdn']['value'] = 'never';
    $_prefs['save_attachments']['value'] = 'always';
    $_prefs['send_mdn']['value'] = '0';
    $_prefs['sortby']['value'] = '100';
    $_prefs['sortdir']['value'] = '1';
    $_prefs['sortpref']['value'] = 'a:1:{s:5:"INBOX";a:1:{s:1:"d";i:1;}}';
    $_prefs['subscribe']['value'] = '0';
    $_prefs['trash_folder']['value'] = 'Deleted Items';
    $_prefs['tree_view']['value'] = '1';
    $_prefs['use_trash']['value'] = '1';

Horde prefs.local.php is:

$_prefs['initial_application']['value'] = 'imp';
    $_prefs['location']['value'] = 'Brisbane, Queensland, Australia';
    $prefGroups['forgotpass']['suppress'] = true;
    $_prefs['timezone']['value'] = 'Australia/Brisbane';
    $_prefs['language']['value'] = 'en_GB';
    $_prefs['language']['locked'] = true;
    $_prefs['date_format']['value'] = '%A, %B %d, %Y';
    $_prefs['time_format']['value'] = '%l:%M:%S %p';