History: Manual cleanup of email bounces

Related: [item3756-Manage-email-bounces]

This will soon be easier: https://gitlab.com/tikiwiki/tiki/-/merge_requests/1879

!! Steps
# Look at most recent bounce
# Determine email address it was sent to.
# Determine type of bounce and course of action
** soft bounce
*** vacation message, just delete message or archive?
** hard bounce
*** email account no longer exists: delete from our system
** other bounces
*** Your mail server is flagged as a spammer. You can contest here: http:// (We should do this once our system stops sending spam)
# Search through whole data set for all uses of that email, and implement decision
** You need to log into each Tiki association site
*** https://tiki.org/tiki-adminusers.php __Generally running latest stable Tiki version__  uses new mail server
**** https://tiki.org/tiki-admin_notifications.php
*** https://dev.tiki.org/tiki-adminusers.php __Generally running latest stable Tiki version__ [https://gitlab.com/tikiwiki/tiki/-/merge_requests/2119|patch applied manually] uses new mail server
**** https://dev.tiki.org/tiki-admin_notifications.php
*** https://doc.tiki.org/tiki-adminusers.php __Generally running latest stable Tiki version__ [https://gitlab.com/tikiwiki/tiki/-/merge_requests/2119|patch applied manually] uses new mail server
**** https://doc.tiki.org/tiki-admin_notifications.php
*** https://themes.tiki.org/tiki-adminusers.php __Generally running latest stable Tiki version__ [https://gitlab.com/tikiwiki/tiki/-/merge_requests/2119|patch applied manually] uses new mail server
**** https://themes.tiki.org/tiki-admin_notifications.php
*** https://profiles.tiki.org/tiki-adminusers.php __Running Tiki 21 LTS__   [https://gitlab.com/tikiwiki/tiki/-/merge_requests/2119|patch applied manually] uses new mail server
**** https://profiles.tiki.org/tiki-admin_notifications.php
*** https://branding.tiki.org/tiki-adminusers.php __Running Tiki 21 LTS__   [https://gitlab.com/tikiwiki/tiki/-/merge_requests/2119|patch applied manually] uses new mail server
**** https://branding.tiki.org/tiki-admin_notifications.php
*** etc.
*** Since ((doc:InterTiki)) is in place, you can manually edit user information. So deactivate InterTiki, clean the data, and reactivate InterTiki. We have a [https://avan.tech/item84889-Tiki-InterTiki-permit-to-modify-user-information-on-nodes|task] to ease this.

!! Things to watch out for
* 1 hard bounce is not necessarily enough to delete email.
* A single bounce message can be for many emails (if you multiple emails to the same domain). So you can't delete it until you have addressed all of it.

!! Essential
* It's great to have a tool to categorize between soft and hard bounce, and count. But we also need to be able to read each email. Thus Cypht access somehow.

!! Potential feature request
* Add an exclusion list for emails never to be written to
** temporary (ex.: 30 days)
** permanent