libesmtp-dev - 1.1.0-3.1~deb12u1 main

LibESMTP is a library to manage posting (or submission of) electronic
mail using SMTP to a preconfigured Mail Transport Agent (MTA) such as
Exim. It may be used as part of a Mail User Agent (MUA) or another
program that must be able to post electronic mail but where mail
functionality is not the program's primary purpose.
.
This package contains the header files and the static version
of the library.