Rust

Send MIME Bytes from a BinData via SMTP

Demonstrates the Chilkat MailMan.SendMimeBd method, which sends an email from caller-supplied MIME bytes held in a BinData. The arguments are the from address, the recipient list (the SMTP envelope recipients), and the BinData containing the MIME. This example loads a .eml file into a BinData and sends it.

Important: When sending caller-supplied MIME, ensure the Message-ID header is unique for each message. Sending MIME whose Message-ID was previously used can cause the message to be silently discarded as a duplicate by mail servers — see chilkatsoft.com/email_duplicate_message_id.asp.

Background: This is the binary counterpart to SendMime (which takes MIME as a string). Working from a BinData is the right choice when the message's raw bytes come straight from a file, a database blob, or a network stream — it delivers them byte-for-byte with no charset conversion that could alter the original, which matters because MIME can carry binary transfer encodings.

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// Demonstrates the MailMan.SendMimeBd method, which sends an email from caller-supplied MIME
// bytes held in a BinData.  The arguments are the from address, the recipient list (the SMTP
// envelope recipients), and the BinData containing the MIME.

let mailman = chilkat::MailMan::new();

// Configure the SMTP server connection.
mailman.set_smtp_host("smtp.example.com");
mailman.set_smtp_port(465);
mailman.set_smtp_ssl(true);
mailman.set_smtp_username("user@example.com");
mailman.set_smtp_password("myPassword");

// Load the MIME bytes to send.  Here we read a .eml file, but the bytes could come from
// any source.
let bd_mime = chilkat::BinData::new();
if bd_mime.load_file("qa_data/eml/message.eml").is_err() {
    println!("{}", bd_mime.last_error_text());
    return;
}

// IMPORTANT: When sending caller-supplied MIME, make sure the Message-ID header is unique
// for each message.  Sending MIME that contains a Message-ID that was previously sent can
// cause the message to be silently discarded as a duplicate by mail servers.  For details,
// see: https://www.chilkatsoft.com/email_duplicate_message_id.asp

// Send the MIME bytes to the envelope recipient(s).
if mailman.send_mime_bd("alice@example.com", "bob@example.com", &bd_mime).is_err() {
    println!("{}", mailman.last_error_text());
    return;
}

println!("MIME email sent.");

// Note: The path "qa_data/eml/message.eml" is a relative local filesystem path,
// relative to the current working directory of the running application.

// Note: Explicitly connecting/authenticating is optional.  Chilkat MailMan automatically
// connects and authenticates -- using the property settings above -- whenever a server
// operation requires it.  Calling the explicit connect/authenticate methods can still be
// helpful to determine whether a failure occurs while connecting or while authenticating.