Horde attachment file size limit

I am running up-to-date UCS server with Horde installed via App Center.
Now a user needs to send an attachment bigger than 2MB, for which the upload is denied.
In Horde Administration $conf[compose][attach_size_limit] is already set to ‘0’ (zero).
Therefor the limit for PHP upload_max_filesize is relevant.

But how can I get that changed so that it is persistent since Horde is running in a docker container?


Hi Jörn,

I thought, the standard limit is 10 MB. But a good beginning would be a look in the Univention Config Registry. Go to the Univention Management Console (Webbrowser) --> System --> Univention Config Registry. Search for “limit” or horde", there what should be to be found the useful.

Or with CLI:
ucr search limit

sample set parameter for 20 MB:
ucr set mail/messagesizelimit=20480000


Hi Dirk,

I already had a look there. Since Horde is dockerized not much parameters found there.
Also via App Settings there are no parameters available to customize the settings I am looking for.

Wanted to disable some of the Horde applications like task manager (nag) or file manager (gollem). Only way I found was entering the docker container and changing configuration there. But those changes are not persisted, due to docker.
Docker requires config changes to be provided from outside of the container.


Hello Jörn,

I have exactly the same problem as you using UCS 4.3 and horde as docker app installed from the app-center.
Did you find any solution? - I would be glad to hear from you!

Hello @ami,
I have posted my solution here: Extend Horde config to disable/enable applications


the attachment upload-size limit is caused by the php.ini settings within the docker container.
There it says:
upload_max_filesize = 2M

I suggest to set this value quite high (as a change in the container image) so that the behavior can be controlled via horde config-files located @/var/lib/univention-appcenter/apps/horde/horde-etc/horde/conf.d or better with a ucr variable.

post_max_size = 8M
hast also to be set to a higher value.
20M would be a good value for my perpective for both settings. Shoud be enough for most people and is still a managable amount.

Filed a bug: https://forge.univention.org/bugzilla/show_bug.cgi?id=49962