Lua

Attach a File with an Explicit Content Type

Demonstrates the Chilkat Email.AddFileAttachment2 method, which attaches a file from the filesystem and lets you explicitly specify its content type rather than having Chilkat infer it from the file extension. This example attaches a binary file as application/octet-stream.

Background: Extension-based type detection is convenient but not always right — a file may have an unusual or missing extension, or you may need a very specific MIME type for the recipient to process it correctly. Specifying the content type explicitly removes the guesswork. application/octet-stream is the generic "arbitrary binary data" type, a safe default that tells the client to treat the attachment as an opaque download rather than trying to render it.

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Lua

local chilkat = require("chilkat")

-- Demonstrates the AddFileAttachment2 method, which attaches a file and lets you
-- explicitly specify its content type instead of letting Chilkat infer it.

local email = chilkat.Email.new()
email.subject = "Email with a file attachment"
email.body = "Please see the attached file."

-- Attach a file, explicitly specifying the content type.
local success = email:add_file_attachment2("qa_data/attachments/data.bin", "application/octet-stream")
if not success then
    print(email.last_error_text)
    return
end

print("NumAttachments = " .. email.num_attachments)

-- Note: The path "qa_data/attachments/data.bin" is a relative local filesystem path,
-- relative to the current working directory of the running application.