Professionals recommend prewarming your cups.
Coffee served in cold porcelain cups offers a taste experience of inferior quality. The smaller the portion (for example an espresso or ristretto), the more important it is to use a prewarmed cup. The cold porcelain instantly takes away heat from the hot, freshly prepared coffee, reducing its temperature by up to 10°, and makes it cool faster. If you add cold cream and sugar to your espresso, and stir it with a cold spoon, the temperature falls by another 10°C, and it will be much less of a pleasure to drink.
In addition, the delightful coffee aroma is inhibited from developing and the coffee will have a less intense fragrance than if served in a prewarmed cup. A warm cup will also retain the crema for longer.
Porcelain cups can be prewarmed very quickly with hot water or steam. However, the most convenient and professional solution is to use a cup warmer.