On few servers Squirrel mail is not behaving properly, like sent mails are not saved, then some buttons will disappear like Save Draft is not there while composing, some buttons will appear like Expunge is there.

So how to control all this, or say if we want to customise things in Squirrel mail and keep them stored which should not get affected by cPanel upgrades.

Server 1
WHM 11.23.2 cPanel 11.23.4-R26138
CENTOS Enterprise 4.6 i686 on virtuozzo - WHM X v3.1.0

Server 2
WHM 11.23.2 cPanel 11.23.4-C26138
CENTOS Enterprise 4.6 i686 on virtuozzo - WHM X v3.1.0
Server 2 with C26138 is having this issue and using ASSP X if that make any difference. Whereas Server 1 is using RvSkin AntiSPAM.

So how to go about it, like if we want to install custom plugins, customise features and keep them stored.