Previously the sent email alerts have been missing mandatory headers
like `Date` and it was also missing content type, content transfer
encoding and mime version. I have taken proper examples form the
unmaintained gomail library to build right emails.
Besides that I have refactored the calls for alerts, they git the same
structure now and it should be prepared to inject custom templates for
all altering methods at some later point. Generally it is prepared for a
more flexible alert handling.
