Did you create an email account? If not you would start by going into "Email Manager " -> "Email Accounts" and create one.
First chose the first part of the email address by entering your desired email into the field user (ie "contact" for instance).
Set your desired password, save this as you will need it when setting the email account up in your email client.
For "E-mail Quota" and "Send Limit" you can leave as it is or tick unlimited (will however be limited to the disk space you have available in the account and a send limit on the plan itself).
Then in the email client (this will differ a bit depending on client) you would fill in the following:
Name: Your name (will be shown as part of the sender, can be anything)
E-mail address: what you just created
Password: the password you set when creating the email address
Protocol: chose
POP3 or IMAP for incoming (IMAP leaves everything on the server and syncs between server and client, POP3 downloads to your computer and depending on setting can keep or remove from the server). For IMAP 993 is the secure port (SSL/TLS) or 143 for plain. For POP3 995 is the secure SSL/TLS port, and 110 the plain one).
SMTP is outgoing emails, 587 is secure (SSL/TLS) or 25 for plain.
Authentication: Password works for me, both incoming and outgoing.
Username: The full email address as you created it, for example
contact@domain.x10host.com.
Server: Your domain name (if you have SSL installed you can use the secure ports, if not you should use the plain to avoid an error about certificate), it will also work to use the servers URL, ie x11.x10hosting.com (assuming you are on x11), which do have certificates installed.
Regarding FTP:
Protocol: FTP
Host: Your domain, or server address as above.
User: Either your DirectAdmin user (as seen in the panel like userhxat @ x##) or if you created an ftp user under FTP manager it would be
chosenname@domain.x10host.com
Password: What your password is (if you don't know the DA password, you can set it by changin password from the panel, just click the service name to get that option), if you created a ftp user you need to set the one you assigned there.
Encryption: FTP over TLS if possible (requires SSL enabled and active), if you have STARTTLS this should also work
Note, my clients are not using the English language so I translated the terms so they may differ on your client(s)