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Once you finish this guide, Gmail sends a copy of every email with an invoice or receipt to your Sintropix Mailbox on its own. Sintropix receives them and uses them in your books, and you never forward anything by hand.
Your Sintropix Mailbox. This guide uses [email protected] as an example. Use your own Mailbox address instead. To find it in Sintropix, open your user menu, go to Configuración → Integraciones (Settings → Integrations), and open your Casilla de correo (Mailbox). If you don’t have one yet, ask your Sintropix contact.
Before you start
  • Use a computer and Gmail on the web (mail.google.com). The Gmail mobile app doesn’t have these settings.
  • It takes about 10 minutes.
  • If Gmail stops you at any step, see Troubleshooting.

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Set up forwarding

1

Open Gmail settings

  1. In the top right, click the gear icon (Settings).
  2. Click See all settings.
Gmail with the Settings gear and the See all settings button highlighted, in the Spanish interface

The screenshots in this guide show Gmail in Spanish. The buttons are in the same place in English.

2

Add your Sintropix Mailbox as a forwarding address

  1. Click the Forwarding and POP/IMAP tab.
  2. In the “Forwarding” section, click Add a forwarding address.
The Forwarding and POP/IMAP tab with the Add a forwarding address button
  1. Enter your Mailbox address, for example [email protected], and click Next.
The Add a forwarding address box with the Mailbox address entered
  1. Google may ask you to confirm it’s you, with your password or a code on your phone. Do that and continue.
Google asks you to verify it's you before it adds the address
  1. In the window that opens, click Proceed, then OK.
Google now sends a confirmation email to your Sintropix Mailbox. Nothing is forwarded until the address is confirmed.
3

Confirm the address

The confirmation email doesn’t arrive in your Gmail. It arrives in your Sintropix Mailbox. Google sends it from [email protected], its subject mentions Gmail Forwarding Confirmation, and it contains a confirmation link.Get the link in one of two ways:
  • Ask Sintropix. Write to your Sintropix contact. They can see the email and send you the link.
  • Find it yourself in Sintropix. Open your user menu and go to Configuración → Integraciones. Open your Mailbox and click Abrir correo (Open mail). Open the email from Google and copy its link.
In Correo, Sintropix’s mail view, the link doesn’t open when you click it. Select it, copy it, and paste it into a new browser tab yourself.
Once you have the link:
  1. Paste it into a new browser tab.
  2. Click Confirm.
  3. Go back to Gmail, open Forwarding and POP/IMAP, and refresh the page. Your Sintropix Mailbox now shows as confirmed.
The email’s subject also has a code in parentheses, such as (#123456789). If Gmail shows you a box for a confirmation code, you can enter that number instead of using the link.
Don’t select “Forward a copy of incoming mail to” on that screen unless you want to forward all your email (see Forward everything instead). The filter in the next step decides what gets forwarded.
4

Create the filter that picks which emails to forward

  1. In the search box at the top, click Show search options (the icon on the right).
The Show search options icon on the right of the Gmail search box
  1. In Has the words, paste exactly this:
  1. To preview which emails match, click Search, then open the search options again.
  2. Click Create filter.
Gmail search options with the criteria pasted into Has the words and the Create filter button
What the criteria do. They pick an email if its subject has one of those words, or if it has an XML file attached. Chilean electronic invoices (DTE) arrive with their XML file. Many receipts from apps and foreign suppliers have the word in the subject even without an attachment. The Spanish words stay in on purpose, because most Chilean suppliers write in Spanish. To change the balance, see Adjust the filter.
5

Forward to your Sintropix Mailbox

  1. In the list of actions, check Forward it.
  2. In the dropdown, choose your Sintropix Mailbox.
  3. Leave every other action unchecked.
  4. Click Create filter.
The filter actions list with the forward option checked
If you see an add forwarding address link next to the forward option instead of your Mailbox, the address isn’t confirmed yet. Go back to step 3.For the first week, Gmail shows a notice reminding you that forwarding is on. That’s expected.

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Emails you already have

Before you create the filter, you see the Also apply filter to matching conversations checkbox. It applies the filter’s other actions to older emails, but it doesn’t forward them.
Google applies a forwarding filter to new email only. Invoices already in your Gmail don’t reach Sintropix when you create the filter. You can leave the checkbox unchecked.
The Also apply filter to matching conversations checkbox
To send older invoices:
  • A few: open each one, click Forward, and send it to your Sintropix Mailbox.
  • Many: talk to Sintropix. You can also connect your Gmail to Sintropix with read-only access, so older email can be searched there.

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Adjust the filter

The recommended criteria cover most cases. For a different balance, paste one of these into Has the words: If a supplier always writes from the same address, add it inside the braces:

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Forward everything instead

If you’d rather not deal with criteria, you can forward all the email you receive. It’s simpler, but Sintropix also receives email that has nothing to do with accounting. You don’t need the filter with this option.
1

Add and confirm your Mailbox

Follow steps 1, 2, and 3 of Set up forwarding.
2

Forward all incoming email

  1. In Forwarding and POP/IMAP, select Forward a copy of incoming mail to and your Sintropix Mailbox.
  2. In the second dropdown, choose keep Gmail’s copy in the Inbox.
  3. At the bottom of the page, click Save Changes.

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Troubleshooting

In Google Workspace, your company’s administrator decides whether users can forward email. Ask them to do this, or do it yourself if you’re the administrator:
  1. Sign in to the Google Admin console at admin.google.com.
  2. Go to Menu → Apps → Google Workspace → Gmail → End User Access.
  3. Click Automatic forwarding.
  4. Check Allow users to automatically forward email to another address. If your console limits forwarding to addresses inside your organization, that won’t work, because Sintropix is outside your company.
  5. Click Save.
If your company uses organizational units, turning it on for the unit of the person who forwards is enough. The change can take a while to apply. If Gmail still blocks you, try again later.
  • In Forwarding and POP/IMAP, check that the address is spelled right. If it isn’t, remove it and go back to step 2.
  • Wait a few minutes and look in Sintropix again. The email can take a moment to show up.
  • If it still doesn’t show up, ask Gmail to resend the verification email from the same screen, and let Sintropix know.
  • If you used the filter: go to Settings → See all settings → Filters and Blocked Addresses, check the box next to the filter that forwards to your Sintropix Mailbox, and click Delete.
  • If you forward everything: in Forwarding and POP/IMAP, select Disable forwarding and click Save Changes.
The Filters and Blocked Addresses tab with the forwarding filter and the Delete button
No. Gmail sends a copy, and your email stays in your inbox as it was: not marked as read, not archived, not deleted. Sintropix doesn’t touch your Gmail either. The only new thing is the copy in your Sintropix Mailbox.Gmail never forwards email that lands in Spam. If an invoice lands in Spam, forward it by hand.

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Sources

The screenshots show Gmail on the web in Spanish (Latin America), taken in October 2026. Google changes its design from time to time, so a button may look slightly different.