CHIP Online gives The Bat! the following characteristics:
“The Bat! is not just an email client. Many email program creators take its functionality as a benchmark; many IT analysts compare newly-appeared email clients with The Bat!.
The Bat! can easily compete with many email clients. Program works perfectly with Cyrillic encodings that cause problems for many other email utilities. Unlimited number of email accounts can be processed using The Bat!. Besides, The Bat! manifests great mail sorting options. An outstanding message dispatcher allows deleting letters directly from the server without downloading them to the local machine.”
The original version of CHIP Online short review of The Bat! is in Russian. You may view it here and here