How did this email reach my Gmail address?

These days people have multiple email accounts, so, one of the common questions posed in the Gmail Help Community is often about "How did this email, that was intended for my account X, reached my Gmail account?" 

The common reasons which can cause this to happen are:

1. Emails are forwarded from the account X to the Gmail account
2. Emails are fetched via POP3 from account X by the Gmail account
3. Emails are fetched via the Gmailify option from account X by the Gmail account
4. Emails are fetched via the ShuttleCloud API from account X by the Gmail account
5. The Gmail address is listed as a Reply-to address in account X
6. The Gmail address is included as a BCC recipient in the email

For anyone inconvenienced by this issue, the most accurate way is to analyze the header of the message they received in their Gmail address. The header lists the machines (or servers) that a message had to pass through before reaching the recipient’s mailbox thereby providing a log of how it ended up in the inbox of the Gmail account.

To analyze the message header, one would need to obtain the message header. Thankfully, Gmail provides a comprehensive help article on how you can do that; not just for Gmail, but also for other mail services under the View your email's full headers section.

Additionally, Google also provides a message header analyzer at https://toolbox.googleapps.com/apps/messageheader/, making it a simple copy-paste exercise - something even the most basic users can perform without any difficulty.

The reason I wanted to reference message header upfront is because of the fact that I will reference some of the header fields that are mentioned in the message headers. The header fields help us understand what the information they contain is about and with regards to. Some of the common header fields we can find in the message header are Delivered-to, Received, ARC-Authentication-Results, Return-Path, Message-Id, In-Reply-To, Content-Type, etc.

Emails are forwarded from the account X to the Gmail account

There are several ways to check this. One can check under the Forwarding settings in account X. 

If account X is a Gmail address, a search for the X-Forwarded-For header field in the message header should display the account X detail and the X-Forwarded-To header field your Gmail address. 

Emails forwarded from my Hotmail address shows a Resent-From header field instead of the X-Forwarded-For header field we see for the Gmail address. 

Yahoo no longer allows automatic forwarding of emails in free Yahoo Mail accounts from January 15, 2021, and no Forwarding settings exists for AOL either. 

Note: It is possible that other providers may use different custom headers. If so, searching for account X in the message header may help disclose the context.

Emails are fetched via POP3 from account X by the Gmail account

This can be confirmed by visiting the Accounts and Import tab under the Gmail account settings - https://mail.google.com/mail/#settings/accounts and checking out if the details under the Check email from other accounts section mention account X (POP3).

Otherwise, the X-Gmail-Fetch-Info header field in the message header should display the account X details.

Emails are fetched via the Gmailify option from account X by the Gmail account

This can also be confirmed by visiting the Accounts and Import tab under the Gmail settings - https://mail.google.com/mail/#settings/accounts and checking out if the details under the Check email from other accounts section mention account X (Gmailify). 

Another option is to search in the message header for the X-Apparently-To header field which should reference account X.

Emails are fetched via the ShuttleCloud API from account X by the Gmail account

Like the Gmailify option, this can be confirmed by visiting the Accounts and Import tab under the Gmail settings;https://mail.google.com/mail/#settings/accounts and checking out if the details under the Check email from other accounts section mention account X. 

Another option is to search for the X-Apparently-To header field in the message header which should reference account X.

The Gmail address is listed as a Reply-to address in account X

Nothin shows up in the message header, so this can be checked by visiting the settings for account X and check if your Gmail account is listed as the Reply-to option for emails sent from that address. 

If account X is a Gmail address, you’d need to visit the Accounts and Import tab under the Gmail settings - https://mail.google.com/mail/#settings/accounts and checking out if the email options details under the Send mail as section includes a Reply-to entry mentioning your Gmail address.

Note: One important thing to keep in mind is, if this is the reason, it will only affect replies and not new emails.

The Gmail address is included as a BCC recipient in the email

Depending on the sending domain, there can be different results.

Sending from a Gmail address, this can be confirmed by opening the email and looking at the message details information as shown in the screenshot below:

A Bcc: header field will show up in the message header, referencing your Gmail address. 

Note: The Bcc: header field will only appear in the individual email addresses which are included as Bcc recipients referencing that particular email address.

When a Bcc email is sent from a Yahoo and AOL address, instead of a Bcc: header field, we see a for clause under the Received: header field that references the Gmail address.

No such details show up when a Bcc email is sent from a Hotmail address. So, when you come across a message header where you neither see the Bcc header field nor the for clause under the Received header field, you would just need to get this possibility checked with the sender of the message.

Finally, if messages intended for your Gmail end up in one of your non-Gmail email addresses, the issue can be resolved by opening the message header, running a search for your Gmail address and then checking the header field against which it is displayed. 

Last updated on: April 13, 2024.