[Feature]: exclude specific senders from archiving (sender filter list)

[Ivann136]

Is your feature request related to a problem?

Some synced mailboxes receive a lot of low-value mail (newsletters, automated
notifications, monitoring alerts, etc.). Currently every message on a synced
account is archived, so these emails inflate the archive size and add noise to
search results, even though I never need to keep them. I have no way to tell
Mail Archiver "archive this account, but skip messages from this sender".

Describe the solution you'd like

The ability to define a list of sender exclusion rules that are evaluated
during synchronization. When an incoming email's sender matches a rule, the
message is skipped and not stored in the archive.

Matching should support:

• an exact address (e.g. noreply@example.com),
• a whole domain (e.g. @example.com),
• ideally a simple wildcard (e.g. *newsletter*@example.com).

Rules could be defined per account (since Mail Archiver is multi-account), with
an optional global list applied to all accounts. A per-account list alone would
already cover most needs.

Additional context

Two points worth considering:

• Interaction with retention policies: an email that is intentionally excluded
  from archiving must NOT be deleted from the mail server by the
  retention/auto-deletion feature. Otherwise it would be lost without ever being
  stored. Excluded messages should simply be left untouched on the server.
• It would help if skipped emails are counted or logged, so users can confirm a
  rule is working as expected.

This complements the existing retention features by giving finer control over
what gets archived, not just how long it is kept. Matching on the From
header covers the main use case; it could later be extended to To/Subject.

I'm happy to help discuss the design or contribute if this is accepted.