Find replacement for t3a-members

We will replace Sympa and merge it into the new tool at https://talk.typo3.org/.

It is not possible to operate 1:m communication like used for t3a-members with this solution. Also it is not possible to set the subscribers list via a script.

Therefore, we need to look out for a new tool:

Mailtrain - https://mailtrain.org/
Check if we can use a hosted solution such as Mailchimp or Hubspot

INFO: The CMS and Security teams are in a very similar situation while they need to replace the Mailman list typo3-announce with something new. See #35 (closed).

Tasks

Get in touch with the T3A board and explain the problem
Define requirements
Decide for a tool
Migration

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information