I'm a bit confused as I'm sending e-mails within CPanel's Roundcube, and then I want to check or answer from that mails in another mail client (in this case were Thunderbird and LG Android mail client) but they don't appear there!!
Why could happen that if desktop mail client had the account configured with IMAP protocol??
Thanks in advance.
There apparently was an issue in the past, but this should be fixed if you're running the latest version.
There may be different folders for sent messages. Maybe not al of them are shown in Thunderbird, so you can try right-clicking on your account's e-mail adress in TB's folder list and check everything in "Subscribe…". This could help in some cases.