Revert "mail: use dovecot-exporter on frontend too"
"Note that statistics are collected only on backends so stats service doesn't do anything on directors and proxies."
https://wiki.dovecot.org/Statistics/Old
This reverts commit cbf6fa85.
"Note that statistics are collected only on backends so stats service doesn't do anything on directors and proxies."
https://wiki.dovecot.org/Statistics/Old
This reverts commit cbf6fa85.