Forward Emails by Sender, Subject, or Content

You probably do not want to forward every single email to someone else. You want to forward some of them, invoices to your accountant, client messages to your team lead, urgent alerts to your personal phone. The rest should stay in your inbox where they belong.

TrekMail makes this easy with conditional forwarding. You set up a mail filter that watches for specific emails and automatically forwards just those to another address. Everything else is untouched.

This guide shows you exactly how to do it, with real-world examples you can copy and adapt.

Unconditional vs. conditional forwarding

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

Unconditional forwarding is on the Forwarding tab after you choose Manage for a mailbox. It forwards every email that arrives in that mailbox to another address. This is useful when you want a complete mirror of a mailbox during a migration or while consolidating inboxes.

Conditional forwarding is set up on the Filters tab. It forwards only emails that match conditions you define. This guide covers that option.

If you are not sure which one you need, ask yourself: "Do I want every email forwarded, or just some?" If the answer is "just some," you want a filter.

Real-world use cases with step-by-step setup

Here are four common scenarios. Each one includes the exact settings you need to enter in TrekMail.

Use case 1: Forward invoices from a vendor to your accountant

The situation: You receive monthly invoices from FreshBooks. Your accountant Sara needs a copy of each one, but you do not want to manually forward them every time.

How to set it up:

1. Go to Mailboxes, find the mailbox, and choose Manage.
2. Click the Filters tab, then click + Add filter.
3. Name the filter: Forward FreshBooks invoices to Sara
4. Set the condition:
   • Field: From
   • Comparison: contains
   • Value: freshbooks.com
5. Set the action:
   • Action: Forward a copy to
   • Value: sara@myaccountant.com
6. Check Stop processing further filters.
7. Click Save filter.

From now on, every email from FreshBooks will automatically be copied to Sara. You will still have the original in your mailbox.

Optional upgrade: Add a second action to also move the email to an "Invoices" folder. Click + Add action, choose Move to folder, and select the folder. Now invoices are forwarded to Sara and organized for you at the same time.

Use case 2: Forward emails from a specific client to your team

The situation: You manage a client account for Acme Corp. Your project manager needs to see every email they send you, but you do not want to CC them manually on every reply.

How to set it up:

1. Go to Mailboxes → choose Manage for the mailbox → Filters → + Add filter.
2. Name the filter: Forward Acme Corp to project manager
3. Set the condition:
   • Field: From
   • Comparison: contains
   • Value: acmecorp.com
4. Set the action:
   • Action: Forward a copy to
   • Value: pm@myagency.com
5. Check Stop processing further filters.
6. Click Save filter.

Every email from anyone at Acme Corp (sales, billing, their CEO, anyone with an @acmecorp.com address) gets copied to your project manager.

Use case 3: Forward urgent emails to your personal phone

The situation: You want emails with "urgent" in the subject line to reach you immediately, even when you are away from your desk. Your phone has a personal email address that pushes notifications.

How to set it up:

1. Go to Mailboxes → choose Manage for the mailbox → Filters → + Add filter.
2. Name the filter: Urgent to phone
3. Set the condition:
   • Field: Subject
   • Comparison: contains
   • Value: urgent
4. Set the action:
   • Action: Forward a copy to
   • Value: yourname@gmail.com
5. Optionally add a second action: Mark as flagged (so it also stands out when you check your TrekMail inbox later).
6. Check Stop processing further filters.
7. Click Save filter.

Now any email with "urgent" anywhere in the subject line gets a copy sent to your personal email and shows up flagged in TrekMail.

Tip: If people in your organization use a specific tag like "[URGENT]" or "PRIORITY," use that as your value instead of a common word. The more specific your condition, the fewer false matches you will get.

Use case 4: Forward order confirmations to a CRM inbox

The situation: Your team uses a CRM that has an inbound email address for logging interactions. You want purchase confirmations and receipts to automatically appear in the CRM.

How to set it up:

1. Go to Mailboxes → choose Manage for the mailbox → Filters → + Add filter.
2. Name the filter: Order confirmations to CRM
3. Set the match type to Any condition (because you want to catch emails that match any of these patterns, not all of them at once).
4. Add your conditions:
   • Condition 1, Subject contains order confirmation
   • Condition 2, Subject contains receipt
   • Condition 3, Subject contains purchase confirmed
5. Set the action:
   • Action: Forward a copy to
   • Value: inbox@yourcrm.com
6. Click Save filter.

This casts a wider net by using "Any condition," so an email matching any one of those three subject patterns gets forwarded to your CRM.

"Forward a copy" vs. "Forward (no copy)": which one should you use?

These two actions sound similar but behave very differently:

Forward a copy to sends a duplicate of the email to the target address. The original email stays in your mailbox. You can read it, reply to it, and organize it as usual. This is the safer and more common choice.

Forward (no copy) redirects the email to the target address and removes it from your mailbox entirely. It is as if the email was never delivered to you. Use this only when you genuinely do not need to see the email at all, for example, routing support tickets to a shared queue that you monitor separately.

Our recommendation: Start with "Forward a copy to." You can always switch to "Forward (no copy)" later once you are confident the email is being handled elsewhere and you truly do not need a local copy.

What happens to the forwarded email?

A few things you might be wondering about:

Does the original sender know the email was forwarded? No. Forwarding happens silently on the server. The sender receives no notification that their email was copied or redirected to another address.

Does the "From" address change on the forwarded copy? The forwarded email still shows the original sender's name and address. TrekMail applies the delivery handling needed for a forwarded copy to pass normal security checks. You do not need to configure this yourself.

Can the recipient reply to the forwarded email? Yes. When they hit reply, it goes to the original sender, not to your TrekMail mailbox. This is usually the desired behavior. It keeps the conversation direct.

Gotchas and limits

Before you set up conditional forwarding, keep these in mind:

You cannot forward back to the same mailbox. This includes its active receiving aliases. TrekMail blocks those targets because they would create a delivery loop.

The target address must be valid. When you save a filter with a forwarding action, TrekMail checks that the target email address has valid mail server records (called MX records). If the address does not look deliverable, you will see an error. Double-check for typos.

Forwarding filters have separate limits. On Pro, up to 5 of the 10 filters can contain a forwarding action. On Agency, up to 25 of the 50 filters can contain one. Filters that only move, flag, mark as read, or discard do not count toward that forwarding limit.

Starter plans include direct (unconditional) forwarding only. Conditional forwarding via mail filters requires Pro or Agency. If you are on the Starter plan, you can forward all mail from a mailbox using the Forwarding tab, but you cannot set up filter-based forwarding rules.

Emails caught as spam are not forwarded. TrekMail's spam filter runs before your mail filters. If an email is flagged as spam, it goes straight to Junk and your forwarding filter never sees it. This is actually a good thing. It prevents you from accidentally forwarding spam to your accountant or CRM.

Test broad rules before relying on them. Send a message that matches the rule to a real recipient and verify both the forwarded copy and the original behave as expected. This is especially important for CRM addresses and large mailing lists, which may apply their own delivery rules.

Combining forwarding with other actions

Forwarding does not have to be the only thing a filter does. You can add multiple actions to a single filter. Some useful combinations:

• Forward a copy + Move to folder: The email goes to your accountant AND gets filed in your Invoices folder automatically.
• Forward a copy + Mark as flagged: The email goes to your project manager AND shows up flagged in your inbox so you remember to follow up.
• Forward (no copy) + (nothing else needed): The email is redirected entirely. Since it leaves your mailbox, other actions like "Move to folder" would have no effect.

To add multiple actions, click + Add action in the filter dialog and choose the additional action from the dropdown.

Quick-start summary

If you just want to get a conditional forward running in sixty seconds:

1. Go to Mailboxes → choose Manage for the mailbox → Filters.
2. Click + Add filter.
3. Set one condition (e.g., From contains vendor.com).
4. Set the action to Forward a copy to and type the target email address.
5. Click Save filter.

Done. Matching emails will be forwarded automatically from this point on.