Active Directory/Windows Authentication
MailEnable Integrated Authentication allows you to use Active Directory/Windows Authentication as well as MailEnable's inbuilt authentication. It also allows you to have mailboxes created automatically as users successfully authenticate using Windows Credentials.

APOP Authentication
Usually passwords are sent in clear text over the network.  This means that the data stream can be intercepted and read, however, APOP encrypts the password before it sends it and this changes every time the user logs on - so even if the encrypted password is intercepted by a third party, it cannot be used to log-on.

CRAM MD5 Authentication
CRAM-MD5 is a challenge-response algorithm based on HMAC-MD5.

POP Before SMTP Authentication
Requires users to access their mailbox first before being authenticated to send messages through MailEnable. This process means that users have to be verified before being able to access the mail server to send. This is provided as an alternative to users whose email clients do not support SMTP authentication.

Secure Password Authentication (NTLM Support)
Mail users with Microsoft Outlook or Outlook Express can select the option to use Secure Password Authentication when authenticating against the MailEnable Server. This effectively provides a higher level of password encryption when clients authenticate against MailEnable.

Secure Sockets Layer (SSL) support for SMTP, POP and IMAP Protocols
MailEnable Enterprise Edition 2.0 allows mail clients to connect to the server over SSL, ensuring that mail communications between the mail client and MailEnable are encrypted.

SMTP Authentication
SMTP authentication allows users outside of a domain to use that domain as their SMTP server when sending mail. SMTP Authentication requires that users log in with a valid username and password for that domain before sending mail. SMTP authentication prevents people relaying through the server to send spam.