RoundCube & Horde Usability Issue

[miner]

Hello.

I would like to use either RoundCube, Horde or SquirrelMail for IMAP with vtiger.

The problems are the following:

1) Enabling HTML for Horde for outgoing mail runs the risk of being disabled when cPanel upgrades (I read this on the Internet)

2) RoundCube is currently incompatible because vtiger uses the PHP Timezone parameter (not PHP's) whereas RoundCube uses GMT. RoundCube would need to recognize (use) the php.ini 'date.timezone' to test with vtiger. When tried, this param was not detected within RoundCube and therefore not within vtiger either. (Unix/Apache)

3) It seems SquirrelMail does not include a feature that allows creating outgoing mail using HTML suitable for a shared server so that's not an option at this point.

Is using either RoundCube, Horde or SquirrelMail not viable because of the reasons stated here or is there a workaround?

Thanks.