Enum AuthError 

#[non_exhaustive]
pub enum AuthError {
    Rejected {
        code: u16,
        enhanced: Option<EnhancedStatus>,
        message: String,
    },
    UnsupportedMechanism,
    MalformedChallenge(String),
    Other(&'static str),
}

An authentication-specific failure.

This enum is non_exhaustive so that future SASL mechanisms can add new failure modes without forcing a major version bump.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Rejected

The server rejected the credentials. The reply code (typically 535) and server message are preserved; client credentials are not.

Fields

code: u16

SMTP reply code returned by the server.

enhanced: Option<EnhancedStatus>

Optional enhanced status code (RFC 3463), present only when the session has ENHANCEDSTATUSCODES enabled. For AUTH failures, common enhanced codes include 5.7.8 (authentication credentials invalid) and 5.7.9 (authentication mechanism too weak).

message: String

Server-supplied reply text.

UnsupportedMechanism

The server’s EHLO response did not advertise an AUTH mechanism that this client supports, or did not advertise the specific mechanism the caller asked for.

MalformedChallenge(String)

The server returned a 334 prompt that did not look like a valid base64 challenge.

Other(&'static str)

A mechanism-specific protocol failure that does not fit the other variants. Currently used by SCRAM-SHA-256 to surface malformed server-first / server-final messages, salt or signature decode failures, server-signature mismatch, and out-of-policy iteration counts. The &'static str is a debug aid; callers should not pattern-match on its content (it is not part of the API contract).

Trait Implementations

impl Debug for AuthError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for AuthError

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for AuthError

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<AuthError> for SmtpError

fn from(value: AuthError) -> Self

Converts to this type from the input type.