There is an updated pull request by hills against master on the void-packages repository

https://github.com/hills/void-packages exim
https://github.com/void-linux/void-packages/pull/16333

New package: exim-4.92.3
An initial package of the Exim MTA. The extent of testing is that this
isn't been used to run a full mail server, my only requirement is as
a local MTA for a workstation.

A patch file from https://github.com/void-linux/void-packages/pull/16333.patch is attached