Martin Luther King Day, 19 January 2015, it is a Federal holiday, with both United States government offices and state offices closed in observation. Private companies and offices may independently choose to stay open or may close for the day. It is seen as a big shopping day, with special merchandise sales advertised.

The United States Postal Service (USPS) will be closed for the holiday.

http://about.usps.com/news/events-calend...

United States banks will be closed for the holiday.

http://www.officeholidays.com/countries/...

United Parcel Service (UPS) will provide all regular services.

http://www.ups.com/content/us/en/resourc...

FedEx will provide all regular services.

http://images.fedex.com/us/services/pdf/HolidaySchedule.pdf

Without knowing where you are, it's impossible to answer for sure, but generally it's a Monday so postal services will be delivering.

There is no mail service today in the US due to the holiday.

USPS won't - it is a public holiday in the USA. Royal Mail will in the UK. If you are somewhere else, who knows?

today is TUESDay why would you think there was no mail today?

Didn't get yet.

No