[!!!][TASK] Remove deprecated mail functionality

Resolves: #61783
Releases: master
Change-Id: Iebe604aca73cee6efc834b1e8c678cd49ce265fc
Reviewed-on: http://review.typo3.org/32907
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Markus Klein <klein.t3@reelworx.at>
Tested-by: Markus Klein <klein.t3@reelworx.at>