//! SMTP wire codec: parsing server responses and encoding client commands.
//!
//! # References
//! - RFC 5321 (SMTP)
//! - RFC 1652 (8BITMIME)
//! - RFC 1854 (PIPELINING)
//! - RFC 2034 (Enhanced Status Codes)
//! - RFC 3030 (CHUNKING, BINARYMIME)
//! - RFC 3207 (STARTTLS)
//! - RFC 4954 (AUTH)
//! - RFC 6531 (SMTPUTF8)
pub
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