Definition
MAILS AND DUTIES is a compound heading covering two distinct legal concepts that share no substantive connection beyond their placement in older legal dictionaries:
1. MAILS (postal law context): The condition of a letter or other postal item that has been properly prepared for transmission through the postal system and placed in the custody of the officer or agent responsible for forwarding it. A letter is considered "in the mails" when it has been processed by postal servants and entrusted to the carrier charged with forwarding—not merely deposited by a sender, but received and accepted into official postal custody.
2. DUTIES (Scots law context): Rents or payments due from an estate. In Scottish legal usage, "duties" refers to the periodic monetary obligations owed in connection with landholding—functionally equivalent to rents in English and American property law.
These two meanings are unrelated. Their joint appearance under a single heading reflects an editorial convention in older legal dictionaries of grouping short entries alphabetically rather than any legal connection between the concepts.
Common Confusion
The postal meaning of "mails" should not be confused with the modern shorthand for electronic mail ("email"), nor should the moment a letter enters "the mails" be conflated with the moment a sender deposits or posts it. The legal significance—particularly in fraud statutes and limitations questions—turns on when the item entered official postal custody, not when the sender acted. Separately, "duties" in the Scots law sense is entirely distinct from customs duties, tax obligations, or fiduciary duties as those terms are used in American and English law.
Why It Matters in Research
Researchers encountering this heading in Bouvier's or similar period dictionaries need to recognize immediately that two unrelated concepts are bundled together. Conflating them, or assuming a substantive relationship, will send research in the wrong direction.
For the postal meaning: the definition of when a communication enters "the mails" has significant downstream consequences in mail fraud analysis, statute of limitations calculations, and contract formation by correspondence. The Bouvier formulation—custody by the forwarding officer, not mere deposit—tracks the older common law approach. Modern federal mail fraud doctrine under 18 U.S.C. § 1341 has developed its own substantial body of law around what constitutes "use of the mails," and researchers should not assume the Bouvier definition maps cleanly onto the federal statutory standard without checking intervening case law development.
For the Scots law meaning: American researchers working in comparative or historical property law contexts should note that "duties" as rents reflects a distinctly Scottish conveyancing tradition rooted in the feudal tenure system. The sources Bouvier cites—Stair's Institutes and Ross's Lectures on Conveyancing—are foundational Scots law texts. This usage does not translate into English common law or American property terminology without qualification.
The compound heading is also a reminder that nineteenth-century legal dictionaries frequently compressed short entries, and a researcher stopping at a heading-level search may miss that only half the entry is relevant to the question at hand.
Historical Dictionary Support
Bouvier's provides two separate glosses under this heading with no editorial bridge between them. The postal definition is supported by a Missouri case citation (67 Mo. 169) and cross-references the LETTER entry, suggesting Bouvier treated the postal meaning as the primary one for American legal audiences. The Scots law definition is brief, sourced entirely to Scottish institutional writers, and offered without further elaboration—consistent with Bouvier's practice of noting foreign law usages for comparative reference rather than treating them as operative American doctrine.
No other major American legal dictionaries of the period appear to have given this compound heading independent treatment. The Scots law definition of "duties" as rents appears in isolation in Scottish institutional sources and is not picked up as a term of art in English or American property law dictionaries of the same era.
What the historical sources miss: neither Bouvier nor his contemporaries anticipated the expansion of federal postal law into a primary vehicle for prosecuting fraud. The postal meaning as defined in the dictionary is narrow and procedural; the modern legal significance of "the mails" in criminal and regulatory contexts vastly exceeds what the nineteenth-century definition contemplates.
Jurisdictional Note
The postal custody definition reflects American common law and early federal postal practice. The Scots law definition of duties as rents is jurisdiction-specific to Scotland and has no operative equivalent in American property law. Researchers working in Scottish legal history or comparative property law should consult Stair's Institutes and Ross's Lectures directly rather than relying on Bouvier's compressed summary.
Encyclopedia Cross-Reference
Wire Fraud and Mail Fraud (18 USC 1341, 1343), The Law Mind Criminal Law Encyclopedia — for the developed federal doctrine around use of the mails as an element of criminal liability, which the Bouvier postal definition only distantly anticipates.