Short answer. No. Article 723 of the Civil Code draws a clear line: although you own the physical letters sent to you, publication or dissemination requires the consent of the writer or, if the writer has died, of their heirs. Ownership of the paper is separate from the right to publish the content.
What the law says
Letters and other private communications in writing are owned by the person to whom they are addressed and delivered, but they cannot be published or disseminated without the consent of the writer or his heirs.
Civil Code, Article 723 — Ownership Of Private Letters. Read the full provision →
Two separate rights: physical ownership and publication
Article 723 separates two things that people often assume go together. You do own the letters you receive — they were addressed and delivered to you, and you may keep them, store them, or destroy them. But owning the physical object does not give you the right to publish its contents. The right to authorize publication stays with the writer. This reflects the understanding that a private letter contains the writer's thoughts and voice, and sharing those publicly without permission is a violation of something more than property.
After the writer's death
The publication right does not end when the writer dies. Article 723 extends it to the writer's heirs. So even decades later, publishing private correspondence without the consent of the writer's family can violate this provision. This matters practically for historical research, memoir writing, or disputes within families where old letters surface. The heirs hold the consent right; if there are multiple heirs and they disagree, the matter becomes more complicated and may require legal guidance.
The public interest exception
There is one route to publication without consent: a court order. Article 723 provides that the court may authorize their publication or dissemination if the public good or the interest of justice so requires. This is a narrow exception. A court would need to find that publication serves a genuine public or judicial interest — not mere curiosity, entertainment, or personal vengeance. The default rule is consent; the court exception is for situations where a higher public interest genuinely overrides the writer's privacy.
What counts as publication or dissemination
The rule covers both publication (making the content available to the public broadly, such as in a book, article, or post) and dissemination (distributing or spreading the content to others). Posting a private letter on social media, sharing it in a group chat, forwarding it to third parties as a form of exposure — any of these could qualify. If you are considering sharing correspondence you received and are unsure whether the writer or their heirs would consent, the safer path is to seek that consent or get legal advice before proceeding.