The package openssh-server provides access with both SSH and SFTP (which operates over SSH). Telnet was replaced by SSH many years ago, being incurably insecure. Anything you can do over the local terminal you can also do over SSH. If you configure your router / modem to forward a port to your server, then you can access it securely even from abroad. The only hard part there will be knowing the external IP address to contact, if you do not have a static one. You can look that up before leaving the house and hope that it does not change during your trip or you can use a dynamic DNS service to access it via a host name.
Originally Posted by niall.stronge
For file transfer over SSH, you have SFTP. There is a built-in text client, sftp, in your system and most file managers (Nautilus and others) also have built-in SFTP support. Press ctrl-L in the file manager and then enter the URL:
There are also other SFTP clients like SSHFS which allows you to mount the remote system as a local directory and do file transfers just like working with a local directory.
That would make the home directory of user from the remote server available in the local directory remote
sshfs email@example.com:. /home/user/remote/