You can also find the required DLL in the 32-bit MySQL Connector/C archives.
The hMailServer forum often provides a direct libmysql.dll.zip containing the necessary 32-bit file. How to Install for hMailServer libmysql.dll 32 bit hmailserver download
The most reliable method is to download a 32-bit ZIP archive of an older MySQL version (such as 5.7.36 ) from the MySQL Product Archives . You can also find the required DLL in
The libmysql.dll file is a critical client library required for to communicate with a MySQL database. Because older versions of hMailServer are often 32-bit applications, they specifically require the 32-bit version of this DLL, even if you are running a 64-bit operating system or a 64-bit MySQL server. Where to Download libmysql.dll (32-Bit) The libmysql
Since hMailServer does not bundle this file due to historical licensing restrictions, you must obtain it manually.
Once you have downloaded the 32-bit libmysql.dll , follow these steps to resolve "could not be loaded" errors: libmysql.dll (32-Bit)