What attaching an email means
Attaching an email means sending another person's email message to someone else by including it as a file inside a new email. You are not forwarding it in the normal way — you are treating the entire message (with all its text, headers, and sometimes attachments) as a single file that you send along with your own message.
This is different from forwarding. When you forward, the original email appears inside your new message in a readable format. When you attach, the original email becomes a file (usually with a .eml extension on Windows or .emlx on Mac) that the recipient opens separately. People attach emails when they need to preserve the exact original format, send it to someone outside their email system, or keep it as a record in a specific folder.
The process works slightly differently depending on whether you use Gmail, Outlook, Apple Mail, or another email program, but the basic idea is the same: find the email you want to send, export it as a file, and then attach that file to a new message.
Key Takeaways
- Attaching an email creates a file from the original message that you can send to someone else, different from forwarding it.
- Gmail does not have a built-in attach email feature, but Outlook, Apple Mail, and most other programs do.
- In Outlook on Windows, right-click the email and select "Forward as Attachment" to send it as a file.
- On Mac Mail, drag the email into a new message or use the Message menu to add it as an attachment.
- The recipient will see the original email as a separate file they can open, not as text inside your message.
How to attach an email in Outlook on Windows
Open Outlook and find the email you want to attach. Right-click on it in your inbox or folder list. A menu will appear with several options. Look for and click "Forward as Attachment". A new message window will open with the original email already attached as a file.
Type the recipient's email address in the "To" field, add a subject line if you want, and type any message you need to include. Then click "Send". The original email will arrive as a .msg file that the recipient can open by double-clicking it.
If you do not see "Forward as Attachment" in the menu, you may be using a very old version of Outlook. In that case, you can drag the email directly into a new message window instead — click and hold on the email, then drag it to your new message.
How to attach an email in Apple Mail on Mac
Open Apple Mail and locate the email you want to attach. Create a new message by clicking "File" in the menu bar, then "New Message", or press Command+N. In the new message window, go to the "Message" menu at the top of your screen and click "Include Original". This will add the email as an attachment.
Alternatively, you can drag the email directly into the new message. Click and hold on the email in your inbox, then drag it into the body of the new message window. The email will appear as an attachment file.
Fill in the recipient's address, subject, and any text you want to include, then click "Send". The original email will arrive as an .emlx file.
How to attach an email in Gmail
Gmail does not have a direct "attach email" feature built into the interface. Instead, you have two options. The first is to forward the email normally — open the email, click the three dots menu, select "Forward", and send it. The original message will appear inside your new email in a readable format, not as a separate file.
The second option is to read the email as a file first, then attach it. Open the email, click the three dots menu, and select "read message". This saves the email to your computer as a .eml file. Then create a new message, click the attachment button (paperclip icon), and upload that file from your computer.
Most people use the forward option because it is simpler and the recipient can read the original message directly without opening a separate file.
How to attach an email in other programs
If you use Thunderbird, open the email and right-click on it. Select "Forward As" and then choose "Attachment". A new message window will open with the email attached as a file.
In Yahoo Mail, open the email you want to attach and click the three dots menu. Look for an option like "Forward as Attachment" or "More Options". If you do not see it, forward the email normally instead — Yahoo Mail prioritizes the forward feature over attachment.
For any email program, if you cannot find an attach option, the forward feature will work as a backup. The recipient will see the original message inside your new email rather than as a separate file, but they will still have access to all the original content.
When you might need to attach an email instead of forward
Attach an email when you need to send it to someone who uses a different email system or when you need to preserve the exact original format with all headers and metadata. This is common in legal or business situations where the original email is evidence or needs to be archived in a specific way.
You might also attach an email when you are sending it to a group and want each person to receive the original message as a file they can store separately, rather than having it appear inside your message. Some workplaces require emails to be attached rather than forwarded for record-keeping purposes.
In most everyday situations, forwarding is simpler and more practical. Use attach only when there is a specific reason the recipient needs the email as a separate file.
Troubleshooting common problems
If you right-click an email and do not see an attach option, your email program may not support this feature. Check your program's help documentation or use the forward feature instead. Some older versions of email software do not include the attach option.
If the attached email file is very large, it may hit your email provider's size limit. Most email programs limit attachments to 20 to 25 megabytes. If the file is too large, try forwarding instead, which does not count against attachment limits the same way.
If the recipient cannot open the attached email file, they may not have an email program installed that recognizes .eml or .msg files. Ask them to try opening it with their email program by right-clicking the file and selecting "Open With". If that does not work, forward the email to them instead so they can read it directly in their inbox.
Frequently Asked Questions
Is attaching an email the same as forwarding?
No. Forwarding shows the original email as readable text inside your new message. Attaching creates a file from the original email that the recipient opens separately. Forwarding is simpler for everyday use; attaching is useful when you need to preserve the exact original format or send it to someone outside your email system.
Can I attach multiple emails at once?
Most email programs let you select multiple emails and forward them together, but attaching multiple emails as separate files depends on your program. In Outlook, you can select several emails, right-click, and choose "Forward as Attachment" to send them all in one message. In Apple Mail, you may need to attach them one at a time or use the drag-and-drop method for each one.
What file type is an attached email?
On Windows, attached emails are usually .msg files. On Mac, they are .emlx files. On some programs, they may be .eml files. All of these are email file formats that your email program can open. The recipient does not need special software — their email program should recognize the file automatically.
Will the recipient see the attachments that were in the original email?
Yes. When you attach an email, any files that were attached to the original message come along with it. The recipient will see both the original email and any files that were inside it when they open the attached email file.
Can I attach an email on my phone?
Most phone email apps do not have an attach email feature. Your best option is to forward the email instead. Open the email, tap the forward button, and send it. The original message will appear inside your new email in a readable format.