To enjoy the real flavour and aroma of high quality black tea try taking it without milk or sugar.
Green teas, flavoured teas and herbal infusions should be taken without milk. A mere touch of sugar or honey perhaps, if it is so desired.
It is said that milk was introduced to tea in the 18th century, particularly in Britain, to mask the mustiness of tea which occurred after the long voyage from China.
It then became a habit which spread through the British Empire. Interestingly milk is rarely added to tea in the rest of Europe.
Some teas such as English Breakfast and Irish Breakfast are blended with the expectation that milk will be added.
How you take your tea depends entirely on your taste and your habits. So enjoy it the way you prefer. But PLEASE use good quality tea.