unable to configure IMAP for onebox

can’t configure for onebox.com - always gives an authentication error. No problem with thunderbird or outlook. It seems to need “use encrypted password” checked in the other clients. Can you help? SMTP no problem, but IMAP gives the error.

em client pops up a box saying “Server says NTLM authentication refused” and requests the password / username.

Here are the settings info provided by onebox.

Your Onebox email can be added as an IMAP account to your email client using a few simple settings:

Username: [FULL email address]. For example: name@onebox.com
Password: Your Onebox password
IMAP Server: imap.onebox.com (port 143)
SMTP Server: smtp.onebox.com (port 25)

If you want to use a secure connection, use IMAP port 993 and SMTP port 465:

IMAP Server: securemail.onebox.com (port 993)
SMTP Server: securemail.onebox.com (port 465)

1Account Name: You must fill in the full E-Mail address including the portion after the “@” sign.