[horde] imp & pop3

[yle at softeam.fr]

Hi,

1/ I've some problem to configure my webmail server using a remote pop3 
server with no ssl protocol.
I've read on newgroups and try this option in imp/config/servers.php :
	'protocol' => 'pop3/notls'
It's working fine, but what's this option "notls" ?

2/ Is it possible to configure horde/imp to use the option "leave a copy of 
mail on server" ?

Thanks for your help.
Regards.

Yann