The terms bulk mail and standard mail are interchangeable. They both refer to the Standard Mail class. Advantages of standard mail are significantly lower postage costs versus First Class mail. In order to send your mail at Standard Mail rates you must have either 1) 200 pieces or 2) 50 pounds of mail. The pieces must be uniform and of a non-personal nature (ie. advertisements, catalogs, solicitations, newsletters). USPS delivery time on Standard Mail is 7-10 days. First-Class mail is the type of mail people are most familiar with. This is mail sent with a stamp or meter. First-Class mail is for mail of a personal nature (ie. bills, invoices, letters, etc.) or for pieces that may require speedier delivery. USPS delivery time on First-Class mail is 2-3 days. Other Classes of mail include Express, Priority, Periodicals and Package Services. See the chart below to help assist you in deciding which mail class is best suited to your needs.