Filters

Filters process incoming messages after synchronization. They can also be previewed or run manually against existing stored mail.

Conditions and order

A rule can require all or any of several conditions. Conditions inspect From, To, Subject, or CC with contains, equals, starts with, or ends with. Comparisons are case-insensitive.

Enabled rules run in their displayed order. The first matching rule wins for each message, so place specific rules before broad ones. Sender rules run first; a blocked message is not processed by the normal filter list.

Actions

Active actions are:

• Mark as read.
• Move to trash. The Delete UI action currently uses the same trash destination rather than permanently deleting mail.
• Move to a named IMAP folder.
• Star the message.
• Apply an IMAP keyword label.

Forward and auto-reply appear as planned actions but cannot be enabled until additional SMTP safety controls exist.

Preview, run, and transfer

Preview shows up to 20 recent matches without changing mail. Run now scans existing messages and queues the same IMAP changes as incoming processing. Rules can be exported as versioned JSON and imported with duplicate detection and validation.

Configuration

Item	Setting name	Environment variable	Requirement
Rule conditions	Settings > Filters > Match, Field, Condition, and Value	None	At least one non-empty condition is required.
Rule action	Settings > Filters > Action and, when shown, Target	None	A target folder or label is required for actions that need one.
Rule execution	Settings > Filters > Run now	None	Optional for existing mail; incoming filters run automatically.
Import and export	Settings > Filters > Import or Export	None	Optional.
Remote mailbox changes	Settings > IMAP > Host, Username / Email, and Password	IMAP_HOST, IMAP_USER, and IMAP_PASSWORD, or IMAP_SERVERS	A running worker and writable IMAP account are required to apply flags or moves upstream.

No filter-specific environment variable exists. Rules are stored in PostgreSQL.