Not getting mail from non-default ISP's-newbie Question

[Lindsay]

I am connected to my default ISP by DSL and all is ok there.

I cannot however receive mail from my other ISP's via the DSL as I could
through Windows.   I think it is something to do with the settings in
Tools, Settings, Mail Accounts,  Edit, Receiving Mail, Authenitication
Type (which in Windows was Password).   There seems to be no place where
I can enter or edit individual ISP passwords.  How is that done please.

Linz