Please help us help you and fill where relevant:
Your LimeSurvey version: [see right hand bottom of your LimeSurvey admin screen]
Own server or LimeSurvey hosting:
Survey theme/template:
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I encountered the problem of deactivating, for example, the add file button in sending emails (it is still active, no solution).
I often send invitations to several thousand people which represents a considerable point on the server knowing that I have more than 5000 questionnaires and some exceed 6000 to 30,000 guests per token
Questionnaire managers can, in complete autonomy (there are more than 300 of them), upload numerous files (resource manager and addition of images in the personalized theme).

My server will start to saturate with all these repositories, which are also not standardized (file naming with ç or é, etc.) and which cause problems when copying these files between my Linux servers.
As I cannot follow all these additions and I do not have access to the production servers (I have to travel or ask the operating teams to carry out the interventions (taking into account their schedule), I can only use the LimeSurvey interface as administrator.

Solutions:
1.
The ideal would be to be able to do the same operations as in questionnaire themes (with interfaces and management of branch files), with a preview of the theme, a test and a return after 20 or 30 seconds.
2.
Or use personalized menus with more options on the different elements constituting the forms (buttons, fields) because currently, you can choose to give access to a menu to a group of people (eg: admins) or not .
This is what I did for resource management: only admins can have access (a bit difficult because the personalized menus no longer work in v6.5.x).

We must not forget that those who want to set up LimeSurvey at home are not necessarily programming experts.

So an interface that allows you to manage everything can help (you can also activate this administration functionality via a plugin to avoid touching the heart of LimeSurvey.