| Member | Value | Description |
|---|---|---|
| atExplicitAutoControl | 16 | The control connection attempts to encrypt based on RFC 2228, and if it fails, sends cleartext. |
| atExplicitControl | 4 | The control connection is encrypted based on RFC 2228 |
| atExplicitNormal | 5 | Everything is encrypted after the certificate is sent. |
| atHashLogin | 8 | The User and Password are hashed to add security over a non-secure line. |
| atImplicitControl | 2 | The control connection is always encrypted. |
| atImplicitLogin | 33 | Control is encrypted until the user is authenticated, data is always encrypted. |
| atImplicitNormal | 3 | The maximum security setting and the default. |
| atNone | 0 | No encryption is used. |
| atSecureData | 1 | The data connection is encrypted with SSL |