Mail fraud refers to any scheme which attempts to unlawfully obtain money or valuables in which the postal system is used at any point in the commission of a criminal offence. Mail fraud is a legal concept in the United States Code which provides for enhanced penalty of any criminally fraudulent activity if it is determined that the activity involved using the United States Postal Service.

Internet fraud

Internet Fraud:schemes may also qualify as mail fraud if the mails are being used at any point in the scheme, including a request that a money order be sent to pay for non-existent or undelivered auction merchandise. Many of these schemes are merely variants on the fraudulent mail-order scams in which the merchandise is never delivered as described or delivered at all.

Impersonation

A number of schemes which misrepresent the identity of the sender, delivering forged documents or bogus requests for personal info have also been perpetrated by mail;

One version involves sending bogus forms which claim to be from taxation authorities requesting or demanding banking info in order to collect tax on deposit interest.

Promotional cheques

It looks like a coupon and is formatted to appear like a cheque; "oh look, XYZ long distance company wants to send you $10". Look a little more closely and this supposed "cheque" contains slippery fine-print wording which authorises the company to change your default telephone long-distance carrier or incurs other obligations on your behalf.

Solicitations in the guise of an invoice

Get-rich-quick schemes

Work-at-home scams

Fraudulent charities and "religious" donations.

Theft from the mails