More granular email sending possibilities for event managers

[petterroea]

Is your feature request related to a problem? Please describe.
As leader in ekskom, i send a lot of email. Some times, i want to send email to a bunch of specific people. For example, i would like to send email to all those who selected option X

Describe the solution you'd like
The ability to select among the options people have selected. If no entries are selected, the mail is sent to everyone. If entries are selected, only those who selected that entry will receive the email.

Even better, but outside the scope of a single feature request, is the ability to tag participants with arbitrary tags(such as "Wants manual ticket"), and the ability to send mails to people belonging to these arbitrary tags.

Describe alternatives you've considered
Exporting the emails and hand-crafting the list of whom to mail.

Additional context
None really. We send a lot of mail, we would like more granular control of mail, the typical use-case is a group of people for which a special condition is met. The easiest solution to use the existing "dinner option" system, the more useful option is to also allow arbitrary tags.