The language of the mail is a header

Answer The language of the mail is a header. RFC 3282 defines Content-Language so a message can state the natural language of its content. The header is a label the sender puts on the words. It helps programs and people know which language they are looking at. It does not prove that the person who receives the mail speaks that language, and it does not turn a tag into a segment you should pay for.

The note that started this: RFC 3282, Content Language Headers, RFC 3282.

Language shows up in solo ad pitches as a country and a promise. The file is German, or Spanish, or English-speaking buyers in a place the seller has not named. Sometimes the creative is in one language and the tag, if it exists at all, says another. If you buy solo ads outside your own first language, read the creative yourself or pay someone who can. A tag is not a translation.

The header can list more than one language when the content genuinely uses more than one. A list of languages is still a description of the content. It is not a census of the readers. A seller who pastes three language codes into a header and calls the file trilingual has decorated a message. The file is trilingual only if the people on it read those languages and asked for mail in them.

What does the Content-Language header say?

RFC 3282 defines a header that indicates the natural language of the message content. It is the sender's label on the content. It is not proof that any particular reader speaks that language.

Natural language means a language people speak and write, as opposed to a programming language or a character set. The header uses language tags. A tag can be right while the creative is clumsy, and a creative can be fluent while the tag is missing. Missing is common. Mail goes out every day with no Content-Language header at all. Absence of the header does not mean the letter has no language. It means the sender did not label it.

Readers do not live inside the header. A person can read a language the tag names and still have no interest in the offer. A person can receive a language they do not read because the list was built on a country, a TLD, or a guess. Country is not language. A guess is not a join action.

• The creative and the language tag name the same language.
• The seller explains how the list was built, in a separate sentence from the tag.
• A country is not offered as a language.
• Unlabeled mail is called unlabeled, not universal.

Can a language header define a solo ad segment?

No. A segment is a claim about people. A language header is a claim about the message. People who read a language are not a segment until the list says how they joined and why they qualify.

Segments are how you stop paying to reach everyone when you meant to reach someone. The honest inputs are things the person did. They joined a list in a stated language. They bought a product described in that language. They told a form which language to use. A header your mailer adds at send time is not one of those inputs. It rides on the message you composed. It cannot reach backward and change who is on the file.

If the seller's segment is only a language tag, you are buying a label. Labels are cheap to add and expensive to believe. Ask for the join path. Where did the address enter, what did the person see, and in what language was that page? The answer is the segment. The header is the label on today's letter.

What should a buyer check on a multilingual send?

Read the creative in the language the reader will see, and read the language tag. If they disagree, ask the seller to fix the tag or the creative before the send. A mismatched label is a small lie that is easy to see.

Also read the landing page in that language. A letter in one language that drops the reader onto a page in another is how a click becomes a bounce from the offer, which your tracker may still count as success. Success is a person who understood the page. The header cannot finish that job. You can, by opening the page before you pay.

RFC 3282 is a small header with a modest job. Let it do that job. It tells you what the sender claims about the words. The people are a different question, and they are the question the money is for.