Forwarding loses metadata. Attaching preserves it. Here's how to attach an email to an email in Gmail, Outlook, and Apple Mail, and when it actually matters.
Mary Nguyen
Are you noticing that more people are forwarding emails to us without thinking twice? It seems simple to forward the pasted content of one email into another. Quick, readable, job done. The problem is that a forwarded email arrives scrubbed. The timestamps are gone. The routing data, the trail of servers the email passed through to reach you disappear. The forwarded email may arrive in the recipient's inbox looking the same as the original. But it is not.
That difference rarely matters for daily sharing. When it does matter, a policy request, a legal report, or a phishing IT report, it’s vital. Attaching an email as a file is how you send the whole package properly.
Here's how to attach an email to an email across every platform, and how to know when it's actually worth the effort.
Why attaching an email is different from forwarding one
Think of forwarding as transcribing a letter by hand. Everything important gets copied across, including the words, the meaning and the action points. But the postmark is gone. The envelope is gone. The ink and the paper that could prove it's genuine, all gone. Your email client creates a brand new message and fills it with the original content. Tidy, readable, and missing the one thing that makes it verifiable.
Forensic records specialists flag that forwarding the original overwrites or removes the original metadata, including the timestamps, server path, and authentication data embedded in the header.
Try attaching an email as a .eml or .msg file, and you will see how it sends the original in a packaged file format. When you open it, any attachment and everything inside is saved. It is exactly as it arrived with headers, formatting, original timestamps, and files that came from the original.
Legal and compliance teams increasingly rely on this when an email needs to be reviewed under scrutiny. The content of an email can tell you what was said. The metadata tells you when, who the author was, and whether it's been changed. In short, forwarding loses the second part.
Every method to attach an email to an email
Each platform handles this differently, and the steps aren't always obvious. Some let you drag and drop in seconds. Others route you through a workaround or two. Here's exactly how it works on each one, so you can pick the method that fits how you work.
Gmail drag and drop
Start with a brand new window to compose your email. Drag the email from your inbox straight into the compose window. Gmail does the rest, converts it to a .eml file, attaches it automatically, no download required. The one exception: if the email you're attaching carries files that push the total over 25MB, Gmail routes it through Drive instead of attaching it directly.
Gmail forwarding as an attachment
Check the box next to the email, hit More in the toolbar, then Forward as attachment. Compose window opens, email attached, done. A new email compose window opens with the email already attached. This method works if you want to attach more than one email at once by selecting multiple. Then forward as an attachment, and they all arrive as separate .eml files in a single message.
Gmail mobile
The Gmail app doesn't support this natively. The closest option: open the email, hit the three-dot menu, select Print, and save it as a PDF. It's an extra step, but the content and formatting arrive intact. It preserves and stores visual content and formatting. However, it does not save the full metadata.
Outlook desktop drag and drop
If you open a new message, then open a second window with your inbox, you can drag the email from the inbox to the email compose window. Outlook saves it as a .msg file. It is worth knowing: .msg is Outlook's own format. Other Outlook users open it without any issues. Recipients on Gmail or Apple Mail may need to take an extra step.
Outlook desktop keyboard shortcut
Select the email you want to attach. On Windows, Ctrl + Alt + F does it in one move. On Mac, go to Message > Forward as Attachment. Either way, a new compose window opens with the email already attached. That means no dragging, no exporting.
Outlook web
Compose a new email in one browser tab. Open your inbox in a second. Drag the email from the second tab to the first compose window. If the compose window minimizes, hover the dragged file over it at the bottom of the screen until it reopens, then drop.
Apple Mail desktop
Highlight the email, go to Message in the menu bar, and select Forward as Attachment. A new compose window will appear with the email attached as a .eml. This only works on desktop, iOS Mail doesn't support it natively.
Apple Mail and Gmail on mobile
Both default to the same workaround by saving the email as a PDF through the print menu, then attaching the PDF manually. It's an extra step, but it's the most convenient option when you're not on a desktop.
Proton Mail
Two steps instead of one. Download the email as a .eml from the three-dot menu, then attach it to a new message the same way you'd attach any file. Use the paperclip to attach the files, and upload the downloaded .eml. It will arrive seamlessly on the other end. Not native, but it gets there.
Templates to attach emails to other emails
Attaching a file without a covering note creates more work for the recipient. They are left guessing what you want them to do with it. These templates remove that ambiguity.
1. Sharing background with a colleague
Sometimes a quick summary doesn't cut it. When a colleague needs the full picture on a project or decision, attaching the original email gives them everything in one place: the exact wording, the dates, and the chain of context behind it.
Subject: Background on [project/topic]
Hi [Name],
I am attaching the original email chain from [sender]. Here is the full context about [topic], including the original wording, metadata and dates.
Let me know if you need anything else.
Thank you.
2. Escalating to a manager
When something needs to go up the chain, your manager needs the original, not your version of it. Attaching the email directly means they can read it exactly as it was sent, without anything lost in translation.
Subject: FYI: original email from [sender]
Hi [Name],
I wanted you to have the original email, not a summary. So I have attached it here. Sent by [sender] on [date].
Happy to talk through if useful.
Thank you.
3. Reporting to IT or security
If something in your inbox looks off, don't forward it the usual way. Attaching the suspicious email as a file keeps the full header data intact, which is exactly what your IT or security team needs to investigate it properly.
Subject: Review suspicious email
Hi [Name],
I have attached an email that looks like a phishing attempt. I am flagging it so you can check the headers and source.
Let me know if you need anything from my end.
Thank you.
4. Sending for compliance or legal records
Some emails need to be on record, not just remembered. Attaching the original file preserves the timestamps, metadata, and exact wording that a forwarded or copied message might not, which matters when accuracy is non-negotiable.
Subject: Original email — [project/matter name]
Hi [Name],
I have attached the original email from [sender/company] for the record. Timestamps and full header data are intact in the file.
Let me know if another format would be more useful.
Thank you.
Email forwarding tips
Attaching an email correctly is only half the job. How you send it, what format you use, and what you include alongside it all affect whether it lands the way you intended. These tips cover the details worth getting right.
Always add a line of context: An unexplained .eml arriving in someone's inbox looks like a mistake. One sentence on what it is and what you need them to do with it is the difference between an email that gets acted on and one that sits there.
Check your file format before you send: Gmail produces .eml files; Outlook produces .msg. Desktop email clients can handle .eml without any problems. .msg files are reliable between Outlook users, however, they can be awkward for anyone on a different platform. If you're not sure which one your recipient uses, .eml is the safest choice.
Use this for records, not routine sharing: For most day-to-day context-sharing, a standard forward is faster and easier to read. The attachment approach earns its place in situations where the original needs to be preserved, compliance, legal, IT, or any context where "what was actually said and when" might be questioned later.
Watch the total file size: An email that came with a large attachment will still contain that attachment when you re-package it as a .eml or .msg. Gmail's outgoing limit is 25MB before routing through Drive. Outlook typically caps at 20–25MB, depending on your organization's settings. If the email you're attaching is heavy, consider sending the original attachment separately.
On mobile, PDF is good enough for most purposes: It won't preserve header metadata, but for situations where you just need the content and formatting on record, a PDF export from the print menu does the job.
Professional situations where attaching is the right call
Forwarding handles most things. These are the situations where it doesn't.
Reporting phishing or suspicious emails to IT: Security teams investigating a suspicious email need the header data. This means the routing information, authentication results, and originating IP. A forward strips most of that. An attached .eml gives them the full picture to work with.
Legal or regulatory documentation: In industries where email exchanges are part of an audit trail, the original has to be evidently unaltered. Metadata is frequently used in legal contexts to establish sequence, what was sent before what, and whether a message preceded a decision. A forward doesn’t provide this . An attached file can.
Sharing the exact wording of a vendor or client agreement: When the precise language matters, including pricing, scope, and terms. Attaching the original removes any question about what was actually spoken about. A pasted forward can be edited, intentionally or accidentally.
Onboarding someone to an ongoing project: Bringing a new colleague up to speed on a client relationship or ongoing matter is faster when you can send the original email exchanges as if they were the originals. They get the actual context, not a curated version of it.
Escalating an unresolved dispute: Raising a complaint internally or with a third party can make sending the original email as an attachment harder to deal with. The timestamps and headers are part of the record and trail.
Send it right the first time, every time
Forwarding an email is quick, but it's not always enough. When the original needs to be preserved, whether for a legal record, a security report, or a situation where the exact wording and timestamps matter, attaching it as a file is the right move. The method varies by platform, but the principle is the same: send the whole thing, not just a copy of it.
For day-to-day sharing, a standard forward does the job. For anything where accuracy, accountability, or a full paper trail matters, an attached .eml or .msg file is the version that holds up. And for everything in between, Fyxer keeps your inbox organized and your draft replies ready, so the emails that need your attention are always easy to find.
Attaching emails to emails FAQs
What's the difference between attaching an email and forwarding it?
Forwarding emails simply copies the email's viewable content into a new message. It is fast and readable, but original metadata — timestamps, server path, authentication data — is lost in the process. Attaching sends the original as a file, with everything saved and preserved. Use forwarding for everyday sharing; use attachment when the original needs to be preserved exactly.
What is a .eml file?
A .eml file is the standard format for storing a single email message, including its full header data, body, and any attachments. Gmail, Apple Mail, Outlook and Thunderbird can open .eml format files. Mobile support is less consistent.
What about .msg files from Outlook?
.msg is Outlook's proprietary format. It works well between Outlook users but is not universally readable. Outside of Outlook, .msg files are unreliable. Recipients on Gmail or Apple Mail may not be able to open them at all. If there's any doubt about what your recipient uses, send a .eml instead — it opens cleanly across every major client.
Is there a size limit on emails I can attach?
No limit on the number, but total email size matters. Gmail caps outgoing messages at 25MB before switching to Drive links. Outlook's limit is usually 20–25MB, however, this may vary by organization. An email with heavy attachments of its own can push you over that threshold fast.
Why doesn't mobile support this properly?
Mobile email apps are built around the highest-frequency use cases, including reading, replying, and composing. Attaching an email as a file is a lower-frequency action that most apps haven't prioritized. The PDF workaround covers most practical requirements when you're not at a desktop.
Can Fyxer help manage emails like these on a day-to-day basis?
Yes. Fyxer organizes your inbox and writes draft replies, so the emails that need your attention are easy to find, and the ones that need escalating or documenting don't get buried.
