Email forwarding sends a copy of incoming messages from one address to another. It is used to read mail from several accounts in one place, to move mail when someone leaves a team, and to let a custom domain address such as [email protected] land in a personal mailbox. It sounds simple, but forwarding can break email authentication and cause messages to go to spam, so it is worth understanding. This guide explains how email forwarding works, how to set it up in Gmail, Outlook and Yahoo and for a domain, why forwarded mail sometimes fails SPF and DMARC, and what ARC and SRS do about it.
What is email forwarding?
There are two things people call forwarding, and they behave differently.
- Manual forwarding is when you open a message and click Forward. It creates a new message from you, with the original quoted or attached. It is a normal email.
- Automatic forwarding is a rule or a setting that sends every matching incoming message to another address without your action. This is what most people mean by "set up email forwarding".
Automatic forwarding is done in one of two places. A mailbox rule inside Gmail, Outlook or Yahoo forwards messages that arrive in that mailbox. An alias or forwarder at the server receives mail for an address on your domain and passes it on to another mailbox, often provided by your domain registrar or DNS host.
How to set up email forwarding in Gmail
- Open Gmail on a computer and go to settings, then choose to see all settings.
- Open the Forwarding and POP/IMAP tab.
- Choose Add a forwarding address and enter the address that should receive the copies.
- Gmail sends a confirmation message to that address. Open it and confirm.
- Back in settings, choose to forward a copy of incoming mail, and choose what Gmail does with the original: keep it in the inbox, archive it or delete it.
- Save the changes.
If you only want to forward some messages, create a filter instead (from the Filters tab), and in the filter choose Forward it to with the confirmed address. Google Workspace administrators can also manage forwarding for users in the admin console, and may restrict it. The phone app does not offer these settings, so use the web version.
How to set up email forwarding in Outlook
Outlook on the web and Outlook.com
- Open Settings and go to the Mail section, then Forwarding.
- Turn on forwarding and enter the destination address.
- Choose whether to keep a copy in your own mailbox, then save.
Outlook desktop
Use Rules. Create a rule that applies to messages you receive, add a condition (or none to match everything) and choose the action forward it to people or public group. In Microsoft 365, an administrator may block automatic forwarding to outside addresses for security reasons. If your rule does nothing, ask your administrator.
How to set up email forwarding in Yahoo Mail
Open the settings, go to the mailbox section, and find the option to add a forwarding address for the mailbox. Yahoo asks you to verify the destination address in the same way as Gmail. Some providers limit forwarding on free accounts or require a paid plan, so check Yahoo's current help pages.
How to set up forwarding for a custom domain
If you own a domain and want addresses like [email protected] to arrive in a personal mailbox, you have three common choices.
- Use your registrar or DNS host's forwarding feature. Many include a simple alias service. You create the alias, enter the destination address and the service handles the rest. This often works with the domain's MX records pointing at the host's mail servers.
- Use a hosted mailbox service such as Google Workspace or Microsoft 365, and create an alias or a group address that delivers to a person's mailbox.
- Run your own mail server with a forwarding table. This is more work and needs care with authentication.
The MX records must point to the service that receives the mail for the alias. See DNS records for email for how MX records work. If you change them to start forwarding, the old mailbox may stop receiving mail.
Why forwarded email can go to spam
When a message is forwarded automatically, the forwarding server sends it onward from its own IP address, but the message still claims to come from the original sender's domain. That breaks one of the main checks.
- SPF checks the sending server's IP address against the list published by the domain in the envelope sender. The forwarder is not on the original sender's list, so SPF fails at the final destination. Read the SPF record guide for the basics.
- DKIM survives forwarding if the forwarder does not change the message. The signature travels with the message and can still be verified. If the forwarder alters the subject or the body, for example by adding a footer, the signature breaks.
- DMARC passes if either SPF or DKIM passes and aligns with the From domain. Since SPF fails through a forwarder, the message depends on DKIM. If the sender has not set up DKIM, or the forwarder changes the message, DMARC fails, and a strict policy can send the message to spam or reject it.
This is the reason that senders who publish a DMARC policy should always sign with DKIM, not rely on SPF alone. Our article on authenticating your sending domain explains how.
SRS and ARC: how forwarders cope
Two techniques help forwarders keep mail trustworthy.
- SRS (Sender Rewriting Scheme) rewrites the envelope sender so that it points at the forwarder's own domain. SPF then passes against the forwarder's record, and bounces return to the forwarder, which can pass them to the original sender. It fixes SPF, but it does not help DMARC alignment by itself, because the visible From domain stays unchanged.
- ARC (Authenticated Received Chain) lets a forwarder record the authentication results it saw when the message arrived and sign them. The final receiver can then decide to trust the original results even though SPF or DKIM later fails. It is described in RFC 8617. Whether a receiver acts on ARC is up to the receiver.
As someone setting up forwarding, you can choose a forwarding service that supports these. As a sender, you can reduce risk by signing every message with DKIM and by choosing a DMARC policy that matches your needs. The overview in email authentication explained covers the standards side by side.
Common problems and fixes
| Problem | Likely cause | Fix |
|---|---|---|
| Forwarded mail lands in spam | SPF fails at the destination; DKIM missing or broken | Ask senders to sign with DKIM, or forward with SRS or ARC |
| Nothing is forwarded | The destination was never confirmed, or a rule is wrong | Confirm the address and check the rule order |
| Forwarding option missing | An administrator turned it off | Ask your administrator |
| Replies go to the wrong person | Reply goes to the original sender, not the forwarder | Reply from the account you want the person to see |
| Loop of messages | Two accounts forward to each other | Remove one rule; see mail loops |
| Bounces for forwarded mail | The destination mailbox is full or rejects it | Check the destination and read the bounce |
Security and privacy of forwarding
Automatic forwarding to an outside address copies mail, including sensitive mail, out of the account. Attackers who gain access to a mailbox often create a hidden forwarding rule to keep reading mail after the password is changed. Check your forwarding settings and rules from time to time, and turn on two-step verification. Organisations often restrict external forwarding for this reason. If you forward work mail to a personal account, check your company's rules first, since you may be breaking them.
How to stop email forwarding
Open the same settings where you turned it on, switch forwarding off or delete the rule, and remove the forwarding address. In Gmail the forwarding setting is on the Forwarding and POP/IMAP tab, and filters that forward are on the Filters tab. In Outlook, check both the Forwarding setting and the Rules list. After you disable it, send a test to confirm.
Using forwarding with a sending service
If your application sends mail through a service and replies should reach a person, set a Reply-To address instead of forwarding the whole stream. If you need to read incoming mail automatically, an inbound parsing feature is safer and easier to monitor than a chain of forwards. See inbound parse and the guide to inbound email processing.
Keep forwarded and sent mail trusted Sign every message with DKIM on your own domain so it can survive forwarding.
References and further reading
Frequently asked questions
What is email forwarding?
It is sending a copy of incoming messages from one address to another. Automatic forwarding does this through a rule or setting, and manual forwarding creates a new message from you.
How do I forward email automatically in Gmail?
Open settings, go to Forwarding and POP/IMAP, add a forwarding address, confirm it from the message Gmail sends there, then choose to forward a copy of incoming mail.
Why does forwarded email go to spam?
Forwarding sends the message from a server that the original domain's SPF record does not list, so SPF fails. If DKIM is missing or broken, DMARC fails too.
What are SRS and ARC?
SRS rewrites the envelope sender so that SPF passes at the destination. ARC lets a forwarder record the authentication results it saw so that the final receiver can trust them.
Is automatic forwarding safe?
It copies mail out of the account, so use it with care. Attackers often add hidden forwarding rules after a break-in, so review your rules and use two-step verification.