New postal rates for first-class mail to Mexico will go into effect Sunday, Feb. 3, along with the new postal rates for in-country mail service.

A new 35-cent rate for half-ounce mail to Mexico will be implemented while the one-ounce rate (previously the only increment available for mail to Mexico) will jump to 45 cents, up from 25 cents.In most cases, a two-page letter will qualify for the new half-ounce rate.

Postal officials encourage those mailing letters to Mexico to weigh their letters prior to sending them until they become used to the new rates.

Letters with insufficient postage will be returned to the sender because there is no procedure for collecting postage due on international mail.