Can i mail a 5x7 postcard

Yes, you can mail a 5x7 postcard, but it's not a standard postcard size. In the United States, the standard postcard size is 3.5 x 5.5 inches, and that's what the US Postal Service (USPS) recommends for postcards.

However, the USPS does allow you to mail larger postcards, including 5x7 inch ones, as long as they meet certain requirements:

1. The postcard must be rectangular in shape.
2. The postcard must have a minimum thickness of 0.007 inch (0.18 mm).
3. The postcard must be able to be mailed at the same rate as a standard postcard (currently $0.35 for a 1-ounce postcard).
4. The postcard must have a return address and a mailing address printed on it.

Keep in mind that larger postcards may not fit in standard postcard racks or mailboxes, so they may require special handling. Additionally, some countries may have different postcard size requirements, so be sure to check with the destination country's postal service if you're sending a postcard internationally.

It's also worth noting that while you can mail a 5x7 postcard, it may not be the most cost-effective or efficient way to send a message. A standard 3.5 x 5.5 inch postcard is still the most widely accepted and convenient size for mailing.