Hi, carrier/homing pigeons were and still are a thing. In addition to the post by Celebreth linked already, you may find these posts interesting:
How frequent do pigeons (or other birds) get used to deliver messages during the ancient to medieval era? - in which /u/Cenodoxus takes a look at the suitability of ravens, falcons, and pigeons
How effective and reliable were pigeons as means of communication in WWI? Is it possible to estimate how much was lost/miscommunicated in their use? How were they trained? - in which /u/mikedash discusses the use of pigeons during WWI
Were birds of prey ever trained to intercept carrier pigeons? - in which /u/yosoyunpayaso discusses anti-pigeon warfare during WWII
While there's always more to be said, perhaps this old answer will be of interest while we await further discussion:
How common was the use of messenger birds in the middle ages has /u/Celebreth goes into great detail about the use of messenger birds.