# Methods of Authentication for Mail Servers

<table><thead><tr><th width="243">Authentication Method</th><th>Description</th></tr></thead><tbody><tr><td>(No authentication)</td><td>No authentication is used. This is often used with SMTP servers.</td></tr><tr><td>Standard Authentication</td><td>The Standard authentication method is used.  Passwords are transmitted as clear-text. This method is not supported by SMTP servers.</td></tr><tr><td>APOP Authentication</td><td>Secure APOP authentication. This is supported by most POP3 servers, but cannot be used with other servers like SMTP because APOP is not a SASL method.</td></tr><tr><td>SASL Login Authentication</td><td>SASL LOGIN authentication. It is not secure but is widely supported. Passwords are transmitted as Base64 strings.</td></tr><tr><td>SASL Plain Authentication</td><td>SASL PLAIN authentication. It is not secure but is widely supported. Passwords are transmitted as Base64 strings.</td></tr><tr><td>SASL Cram-MD5 Authentication</td><td>Secure SASL CRAM-MD5 authentication. Might not be supported by particular server implementations.</td></tr><tr><td>SASL Digest-MD5 Authentication</td><td>Secure SASL DIGEST-MD5 authentication. Might not be supported by particular server implementations.</td></tr><tr><td>SASL NTLM Authentication</td><td>Secure SASL NTLM authentication (also known as Secure Password Authentication - SPA). Might not be supported by particular server implementations.</td></tr><tr><td>SASL MSN Authentication</td><td>Secure SASL MSN authentication (equivalent to NTLM). Might not be supported by particular server implementations.</td></tr><tr><td>SASL GSS Authentication</td><td>Secure SASL GSS API authentication (Kerberos). Used to authenticate the current Windows account in Windows domain environments such as Active Directory.</td></tr></tbody></table>

## &#x20;<a href="#determining_a_logging_officer" id="determining_a_logging_officer"></a>