Mail Filters: Auto-Sort Email in TrekMail

Picture this: every morning you open your inbox and spend twenty minutes dragging invoices into one folder, flagging urgent client emails, and deleting newsletters you never signed up for. Now imagine your inbox did all of that for you, automatically, before you even poured your coffee.

That is exactly what mail filters do in TrekMail. They are simple rules you set up once, and from that point on, TrekMail sorts, forwards, flags, or discards incoming messages on your behalf. No manual effort, no forgotten follow-ups, no clutter.

Why filters matter for your business

If you run an agency, freelance practice, or small team, your inbox is mission-critical. Important emails get buried under noise. Filters fix that by making sure every message lands in the right place the moment it arrives.

Here are a few everyday situations where filters save real time:

• Invoices from vendors land directly in an "Invoices" folder so your bookkeeper can find them without asking you.
• Client emails get flagged automatically so you never miss a message from your most important accounts.
• Newsletter digests move straight to a "Read Later" folder instead of crowding your primary inbox.
• Order confirmations forward automatically to a shared CRM inbox so your whole team stays in the loop.
• Spam-like messages that slip through get silently discarded before they waste your attention.

You set the rules. TrekMail does the work.

How a filter works: conditions and actions

Every filter has two parts.

Part 1: Conditions (what to look for)

A condition tells TrekMail which emails the filter should apply to. You pick a field to check, choose how to compare it, and type in a value. For example: "If the From address contains billing@freshbooks.com..."

Here are all the conditions you can use:

For text fields, choose contains, is exactly, matches a pattern, or exists. Size uses is greater than or is less than. The available choices change with the field, so the form prevents combinations that would not work.

Part 2: Actions (what to do)

Once a filter finds a matching email, it performs an action. Here is every action available in TrekMail and what it actually does:

You can combine multiple actions in a single filter. For instance, you could forward a copy to your accountant AND move the original to your Invoices folder, all in one step.

A filter can contain up to 10 conditions and up to 5 actions. The number of saved filters and the number that may contain a forwarding action are separate plan limits.

How filter order and Stop processing work

Filters run from top to bottom, in the order you see them on screen. A matching filter performs its actions. Processing continues to the next filter unless you turn on Stop processing further filters for that rule. A reject action always stops processing because the message is refused.

This means order matters. Here is a quick example of why:

• Filter 1: If Subject contains "invoice" then Move to Invoices folder
• Filter 2: If From contains "bigclient.com" then Mark as flagged

If Big Client sends you an email with "Invoice #4021" in the subject, both filters can act on it. Turn on Stop processing further filters for Filter 1 only when moving the message should prevent the later flagging rule.

To fix this, you could either reorder the filters (put the Big Client filter on top) or combine both conditions and actions into a single filter. The section on reordering filters in our step-by-step guide covers this in detail.

Spam is handled before filters run

TrekMail's spam protection runs before your filters ever see a message. Emails flagged as spam go straight to your Junk folder and are never processed by your filters. This is good news: it means you do not need to create filters to deal with spam, and your filters will not accidentally forward junk mail to your teammates.

If a legitimate email keeps landing in Junk, use the "Not Spam" button to train the filter. Once it is recognized as safe, your mail filters will be able to process it normally.

Filters only apply to new mail

One important detail: filters only act on emails that arrive after the filter is created. They do not go back and reorganize messages already sitting in your mailbox. If you need to sort existing emails, you will need to move them manually (or use your webmail client's search-and-move feature).

Plan availability

Not every TrekMail plan includes active filters. Here is what each plan gets:

Managed mail filters run on Pro and Agency. Nano and Starter can keep up to three filters saved for a later upgrade, but those filters are inactive. Starter includes up to three conditional forwarding rules per mailbox and vacation auto-reply.

Filters vs. the Forwarding tab

TrekMail has two ways to forward email, and they serve different purposes:

• The Forwarding tab (open the mailbox, then choose Manage) forwards every email that arrives in your mailbox to another address. It is all-or-nothing.
• Filters with a forwarding action let you forward only specific emails that match your conditions. For example, forward only invoices, or only emails from a certain client.

If you need selective forwarding, use a filter. If you want a complete mirror of your mailbox sent somewhere else, use the Forwarding tab. Our guide on conditional forwarding walks through the most common scenarios.

Filters and aliases: Filters apply to all mail arriving in your mailbox, including messages sent to your aliases. You don't need separate filters for each alias.

Filters and raw Sieve: A custom Sieve script replaces the managed filter script for that mailbox. If you use the raw editor, return to managed mode before expecting dashboard filters or an auto-reply to run. The raw editor is for Agency-plan users who are comfortable maintaining their own rules.