In Blount v. Rizzi (1971) nullified provisions allowing the postmaster
general to refuse to mail obscene matter. The First Amendment requires
safeguards for protected expression.

In Donaldson v. Read Magazine (1948), the Court said First Amendment
freedoms of speech and press did not prohibit Congress from trying to
prevent mail fraud.

In Ex parte Jackson (1877), the Supreme Court said Congress did not violate
the First Amendment by closing the postal system to literature about
lotteries.

In Grimm v. United States, the Supreme Court upheld on a conviction for
using the mail to convey information about where to purchase pornographic
pictures.

Hannegan v. Esquire (1974) overturned a decision revoking a mail permit
issued to Esquire magazine, affirming First Amendment freedoms of speech
and press.

Hartman v. Moore (2006) said that those who allege their First Amendment
rights are being retaliated against must prove there is no probable cause
for the retaliation.

In re Rapier affirmed that federal statutes prohibiting the use of the mail
to send lottery cards or advertisements do not violate First Amendment
freedom of the press.

Lamont v. Postmaster General (1965) used the First Amendment to invalidate
a federal law allowing the Postmaster General to regulate communist
propaganda through the mail.

Leach v. Carlile (1922), which upheld a mail fraud order, is best known for
a dissent emphasizing that the First Amendment was designed to prevent
prior restraints.

Lewis Publishing Company v. Morgan (1913) said requiring newspapers to
submit the names of editors and owners to the Post Office did not violate
the First Amendment.

Rowan v. U.S. Post Office (1970) held that a person’s right to privacy
prevailed over First Amendment claims of publisher mailing sexual materials
to a person’s home.

The First Amendment case Swearingen v. United States (1896) overturned the
conviction of a newspaper publisher who mailed a newspaper with an
allegedly obscene article.