Enum Error 

#[non_exhaustive]
pub enum Error {
    Io(Arc<Error>),
    Auth {
        text: String,
        code: Option<ResponseCode>,
    },
    No {
        text: String,
        code: Option<ResponseCode>,
    },
    Bad {
        text: String,
        code: Option<ResponseCode>,
    },
    Bye {
        text: String,
        code: Option<ResponseCode>,
    },
    Protocol(String),
    Parse(String),
    Timeout,
    Closed,
    StartTlsUnavailable,
    MissingCapability(String),
    AppendLimit {
        size: u64,
        limit: u64,
    },
    InvalidAppendDate(String),
    Internal(String),
    DriverPanicked(String),
    DriverGone,
}

Error type for IMAP client operations.

Implements Serialize/Deserialize behind the serde feature flag. The Io variant is serialized as its ErrorKind name and message string; on deserialization an std::io::Error is reconstructed from these fields.

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.

Io(Arc<Error>)

Underlying I/O error, including TLS transport errors (RFC 3501 Section 2.1).

Wrapped in Arc so that Error can implement Clone.

Auth

Authentication was rejected by the server (RFC 3501 Section 6.2.2).

The optional ResponseCode carries the structured reason code (e.g., [AUTHENTICATIONFAILED], [EXPIRED], [PRIVACYREQUIRED]) when the server provides one (RFC 5530 Section 3).

Fields

text: String

Human-readable response text.

code: Option<ResponseCode>

Structured response code, if present (RFC 5530 Section 3).

No

Server returned a NO response to a command (RFC 3501 Section 7.1.2).

The optional ResponseCode carries the structured reason code (e.g., [NOPERM], [OVERQUOTA]) when the server provides one (RFC 5530 Section 3).

Fields

text: String

Human-readable response text.

code: Option<ResponseCode>

Structured response code, if present (RFC 5530 Section 3).

Bad

Server returned a BAD response — client sent something invalid (RFC 3501 Section 7.1.3).

The optional ResponseCode carries the structured reason code when the server provides one (RFC 5530 Section 3).

Fields

text: String

Human-readable response text.

code: Option<ResponseCode>

Structured response code, if present (RFC 5530 Section 3).

Bye

Server sent BYE — closing connection (RFC 3501 Section 7.1.5).

BYE responses can include response codes such as [ALERT] or [UNAVAILABLE] that carry actionable information for the client (RFC 3501 Section 7.1.5, RFC 5530 Section 3). The [ALERT] code in particular MUST be presented to the user (RFC 3501 Section 7.1).

Fields

text: String

Human-readable response text.

code: Option<ResponseCode>

Structured response code, if present (RFC 5530 Section 3).

Protocol(String)

IMAP protocol violation by the server (RFC 3501 Section 7 / RFC 9051 Section 7).

Parse(String)

Failed to parse a server response (RFC 3501 Section 7 / RFC 9051 Section 7).

Timeout

Operation exceeded the caller-supplied timeout.

This is a client-imposed constraint, not a protocol-level error. See RFC 3501 Section 5.4 for the server-side autologout timer; client-side timeouts guard against indefinite blocking on I/O.

Closed

The TCP connection has been closed (RFC 3501 Section 2.1).

StartTlsUnavailable

STARTTLS was requested but the server does not advertise it (RFC 3501 Section 6.2.1, RFC 9051 Section 6.2.1).

MissingCapability(String)

A capability required for the requested operation is not advertised (RFC 3501 Section 6.1.1).

AppendLimit

Message exceeds the server’s advertised APPENDLIMIT (RFC 7889 Section 3).

Fields

size: u64

Size of the message the caller tried to append (RFC 7889 Section 3).

limit: u64

Server-advertised maximum in octets (RFC 7889 Section 5).

InvalidAppendDate(String)

The date-time string supplied to APPEND does not conform to the date-time production in RFC 3501 Section 9.

date-time      = DQUOTE date-day-fixed "-" date-month "-" date-year
                 SP time SP zone DQUOTE
date-day-fixed = (SP DIGIT) / 2DIGIT
date-month     = "Jan" / "Feb" / ... / "Dec"
time           = 2DIGIT ":" 2DIGIT ":" 2DIGIT
zone           = ("+" / "-") 4DIGIT

Internal(String)

Internal driver error — the driver task stub has not been replaced by its full implementation yet, or an invariant was violated that indicates a bug in the library.

DriverPanicked(String)

The driver task panicked. The payload is the panic message extracted from the JoinError (best-effort — non-string panics produce a generic description).

DriverGone

The driver task exited (cleanly or via cancellation) and the command channel is closed, but no panic was observed.

Trait Implementations

impl Clone for Error

fn clone(&self) -> Error

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

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<Error> for Error

fn from(e: Error) -> Self

Converts to this type from the input type.

impl From<ValidationError> for Error

fn from(e: ValidationError) -> Self

Converts to this type from the input type.

impl PartialEq for Error

Compares two IMAP errors for equality.

The Io variant compares by std::io::ErrorKind only, since std::io::Error does not implement PartialEq. Two Io errors with the same ErrorKind are considered equal even if their messages differ.

fn eq(&self, other: &Self) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for Error