[imp] Linked attachments don't work as expected

[Benedetto Vassallo]

Hello,
I am recently update my horde installation to horde 5.2.5/imp 6.2.8 and
have an issue when try to send linked attachments.

My imp configuration is:

$conf['compose']['use_vfs'] = true;
$conf['compose']['link_attachments_notify'] = false;
$conf['compose']['link_attach_threshold'] = 5242880;
$conf['compose']['link_attach_size_hard'] = 5242880;
$conf['compose']['link_attach_size_limit'] = 104857600;
$conf['compose']['link_attachments'] = true;
$conf['compose']['attach_size_limit'] = 0;
$conf['compose']['attach_count_limit'] = 0;

When I try to send a single attached file bigger than 5 MB, it works as
expected.
When I try to send, say 3 files of 2 MB each, the response is "Error when
communicating with the server" and the mail is not sent.

In my log I see the following message:

2015-02-27T11:17:06+01:00 EMERG: HORDE [imp] Call to a member function
setRaw() on a non-object [pid 29524 on line 2909 of
"/var/www/horde5/imp/lib/Compose.php"]
2015-02-27T11:17:06+01:00 DEBUG: HORDE 1.
Horde_ErrorHandler::catchFatalError()

If I click again the "Send" button, I got an error
like "unable to create vfs file .horde/imp/compose/xxxxxxx".
In fact the file is created in the vfs storage.
My vfs storage type is file, and the base directory is owned by
apache:apache and have 750 permissions.
My Linux distro is CentOS Linux release 7.1.1503 (Core)
My apache version is httpd-2.4.6-31.el7.centos.x86_64
My php version is 5.5.25

I hope this can help you to find the cause of this issue.

Thank you in advance for any solution.
Best regards.
-- 
Benedetto Vassallo
Responsabile U.O.B. Sviluppo e manutenzione dei sistemi
Sistema Informativo di Ateneo
Università degli studi di Palermo

Phone: +3909123860056
Fax: +390916529124