Enum MessageValidationError 

#[non_exhaustive]
pub enum MessageValidationError {
    MissingFrom,
    SenderWithoutFrom,
    MissingRecipients,
    #[non_exhaustive]
    ReservedHeaderName {
        name: String,
    },
    SubjectContainsInvalidChars,
    #[non_exhaustive]
    MailboxDisplayNameContainsInvalidChars {
        location: &'static str,
    },
    #[non_exhaustive]
    AttachmentMetadataContainsInvalidChars {
        field: &'static str,
    },
}

Reasons a Message failed Message::validate_basic (and therefore cannot be promoted into an OutboundMessage).

use email_message::{Address, Body, Header, Mailbox, Message, MessageValidationError};

let from: Mailbox = "alice@example.com".parse()?;
let to = Address::Mailbox("bob@example.com".parse()?);

// A subject carrying a CRLF injection is rejected at build time:
let error = Message::builder(Body::text("hello"))
    .from_mailbox(from.clone())
    .add_to(to.clone())
    .subject("hi\r\nBcc: attacker@example.com")
    .build()
    .unwrap_err();
assert_eq!(error, MessageValidationError::SubjectContainsInvalidChars);

// A custom header that collides with a structured field is rejected:
let error = Message::builder(Body::text("hello"))
    .from_mailbox(from)
    .add_to(to)
    .add_header(Header::new("Subject", "shadow")?)
    .build()
    .unwrap_err();
assert!(matches!(
    error,
    MessageValidationError::ReservedHeaderName { ref name, .. } if name == "Subject"
));

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.

MissingFrom

The message does not have a From mailbox.

SenderWithoutFrom

A Sender mailbox is set without a From mailbox.

MissingRecipients

None of To, Cc, or Bcc contains a recipient.

#[non_exhaustive]

ReservedHeaderName

A custom header duplicates a structured message field.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

name: String

Conflicting custom header name.

SubjectContainsInvalidChars

The subject contains a raw newline or forbidden control character.

#[non_exhaustive]

MailboxDisplayNameContainsInvalidChars

A mailbox or group display name contains header-unsafe characters.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

location: &'static str

Message field containing the invalid display name.

#[non_exhaustive]

AttachmentMetadataContainsInvalidChars

Attachment metadata contains header-unsafe characters.

Fields

Non-exhaustive enum variants could have additional fields added in future. Therefore, non-exhaustive enum variants cannot be constructed in external crates and cannot be matched against.

field: &'static str

Invalid attachment metadata field.

Trait Implementations

impl Clone for MessageValidationError

fn clone(&self) -> MessageValidationError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for MessageValidationError

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

Formats the value using the given formatter.

impl Display for MessageValidationError

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

Formats the value using the given formatter.

impl Eq for MessageValidationError

impl Error for MessageValidationError

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 PartialEq for MessageValidationError

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for MessageValidationError