Struct SmtpConnection 

pub struct SmtpConnection { /* private fields */ }

SMTP client connection for outbound delivery

Implementations

impl SmtpConnection

pub async fn connect(host: &str, port: u16) -> Result<Self>

connect to an SMTP server and read the greeting

pub async fn connect_with_timeout( host: &str, port: u16, timeouts: &TimeoutConfig, ) -> Result<Self>

connect with explicit timeout configuration

pub fn is_tls(&self) -> bool

returns true if the connection is using TLS

pub async fn ehlo(&mut self, hostname: &str) -> Result<SmtpResponse>

send EHLO and return the response

pub async fn starttls(self, hostname: &str) -> Result<Self>

Upgrade to TLS via STARTTLS — classic API returning the upgraded connection or an opaque io::Error.

Internally delegates to Self::try_starttls. Callers that want structured TLS-failure classification (for TLSRPT reporting, metrics labels, etc.) should call try_starttls directly.

pub async fn starttls_dane( self, hostname: &str, tlsa_records: Vec<TlsaRecord>, ) -> Result<Self>

Upgrade to TLS via STARTTLS with DANE TLSA verification — classic API. See Self::try_starttls_dane for the structured variant.

pub async fn try_starttls(self, hostname: &str) -> StarttlsResult

Upgrade to TLS via STARTTLS, returning a structured StarttlsResult that discriminates between server-side rejection (connection still usable) and handshake failure (connection unrecoverable, must reconnect). On handshake failure, the wrapped TlsOutcome is RFC 8460 §4.3-aligned so callers can build TLSRPT reports directly.

pub async fn try_starttls_dane( self, hostname: &str, tlsa_records: Vec<TlsaRecord>, ) -> StarttlsResult

Upgrade to TLS via STARTTLS with DANE TLSA verification, returning a structured StarttlsResult. DANE-specific certificate rejections are reported as TlsOutcome::DaneValidationFailure rather than the PKIX CertificateNotTrusted so TLSRPT reports can distinguish tlsa-invalid from generic untrusted-CA failures.

pub async fn deliver( &mut self, from: &str, to: &[&str], message: &[u8], ) -> Result<SmtpResponse>

send MAIL FROM, RCPT TO, DATA, and message body

pub async fn quit(&mut self) -> Result<()>

send QUIT