Attaching one email to another is useful in many situations. You may need to share the full message history with a colleague, send it to support, or preserve the original header details. Doing this properly ensures context, dates, sender information and attachments remain intact. This guide walks through methods usable in Gmail, Outlook, Apple Mail, and other email clients. You will learn how to attach entire emails as files or convert them to standard formats like EML or PDF. Even on mobile, you can still share emails securely and efficiently.
Why You Might Need to Attach an Email to Another Message
Many users default to forwarding the content when sharing an email. But forwarding changes formatting and may omit headers, metadata or attachments. If someone needs the original fully intact, attaching the message is better. Use attachment when:
- You’re tracking support issues and need full context.
- You want to share internal chain of communication without editing.
- You must preserve native files or headers for auditing or legal reasons.
- You’re transitioning between clients and need to export emails.
This approach treats each email as a standalone document. It avoids confusion when the original message included images, signatures, or formatting that reply or forwarding may strip. In collaborative environments or professional communication, attaching the email ensures clarity and accountability.
Understanding Email Attachment Formats
Common formats for attaching emails include EML, MSG, or PDF. EML and MSG preserve native email content including headers, attachments, embedded images, and metadata. PDF is useful when recipients only need to read the content, not import it. Some clients cannot open EML or MSG directly, so PDF offers a fallback option.
EML is supported by most desktop clients: Outlook, Thunderbird, Apple Mail, and others. MSG is specific to Outlook on Windows. Saving an email as EML or MSG maintains full fidelity. When you attach it to another email, the recipient can open it with a compatible client or convert it again.
Converting email to PDF flattens the message visually. It becomes easily viewable on most platforms, but the recipient cannot easily re-import the content. Use PDF when preserving layout for reference or archival. It also helps when sharing with people who only need read-only access.
Understanding the format you choose helps you match method to user needs. For compatibility across platforms, PDF works best. For data fidelity, EML or MSG is preferred.
Attaching an Email as a File in Gmail (Web & Mobile)
In Gmail’s Web version, attaching an email as a file involves downloading it first and then attaching. First, open the email to attach, click the three-dot menu (More), and select “Download message” to save it as an EML file. Compose a new email, click the paperclip icon, attach the downloaded EML, and send. The recipient with a compatible email client can open it as the original message.
Gmail mobile does not support direct attachment of other emails. However, you can forward or convert email to PDF manually. Alternatively, use the Gmail web interface on mobile browser to download the EML and then attach via another app or upload from device storage.
If you need to forward rather than attach on mobile, you can reply to yourself or use printer-to-PDF workflow: choose “Print”, then when the printer options appear, use “Save as PDF”, and attach that file. That wraps the email into a PDF document. This method is especially helpful when sharing read-only content.
Incorporating an Email into a New Message in Outlook (Desktop & Web)
Outlook desktop makes this process easy. In the desktop app for Windows or Mac, select the email you want to attach, then navigate to Message > Actions > Forward as Attachment. This creates a new compose window with the original email attached as .MSG or .EML, along with any included files. Fill in the recipient and message, then send. This keeps full fidelity of the original message.
Outlook Web (OWA) does not have a direct “Forward as Attachment” option. Instead, you can drag and drop the message from the message list into a new message window. This action attaches the message file (.eml) automatically. Alternatively, click the three-dot menu on the email, choose “Download EML”, then compose a new message and attach the file manually.
Outlook mobile app also does not support attaching emails directly. Use the web version in a mobile browser, or manually download and attach the EML via other apps or workaround solutions. For most accurate results, complete attachment from desktop or web environment.
Forwarding Entire Emails as Attachments in Apple Mail (macOS & iOS)
On a Mac, Apple Mail makes attaching easy. Select the messages you want to send, then drag them into a new message window. They become .EML attachments. You can also use the File > Save As menu to export selected mails as EML files, then attach them manually in a new mail.
In iOS Mail app, attaching emails directly is not supported. Instead, open the email, use the share icon, and save it as PDF. Then start a new email and attach that PDF. Alternatively, forward normally if detail is not critical. For full-feature fidelity, use your Mac or another desktop environment to export and attach.
Using PDF or EML Format to Attach Emails Manually
When native email clients don’t offer a direct option to attach one email to another, saving the original email as a file becomes the solution. The two most common manual formats are PDF and EML. Both can be saved locally and added to any email as a traditional file attachment. The steps vary slightly by client and device, but the principle remains the same.
Here is a simple step-by-step approach to attaching an email manually using both PDF and EML formats:
- Open the email you want to attach.
Start in your email client and navigate to the email that needs to be shared. - Choose “Save As” or “Download.”
In Gmail and many others, use the “More” or three-dot menu and select “Download message” or “Save as EML.” In Apple Mail or Outlook, use the File menu to “Save As” or drag the message to your desktop. - If using PDF, select “Print” and then “Save as PDF.”
On macOS and Windows, use the print dialog and change the destination to “Save as PDF.” This turns the email into a readable document. - Compose a new email.
Open a new message and address it to the intended recipient. - Use the attachment (paperclip) icon.
Click the attach icon and choose the saved EML or PDF file from your device. - Send your message.
The recipient will now receive the original email as an attachment; either in native format (EML) or a viewable document (PDF).
This method works across all modern clients, even mobile apps, when cloud storage or desktop file transfer is available. For mobile, PDF is often easier, as fewer apps open EML files directly.
To learn more about using PDF as a long-term storage or sharing method, check this helpful internal guide, Save Email as PDF. It outlines cross-device steps for converting and attaching PDFs reliably.
Tips for Attaching Emails in Other Clients (Yahoo, Thunderbird, etc.)
Different email clients vary in how they allow users to attach emails. For example, Yahoo Mail does not offer a native “Forward as Attachment” feature. However, you can still save an email as a file and attach it manually. This typically involves using the browser’s print-to-PDF option or using the “Download message” feature if available.
Mozilla Thunderbird, a desktop email client, supports dragging and dropping one message into another as an attachment. You can also right-click an email, choose “Save As,” and store it in EML format for reuse. This is especially useful in professional workflows where email chains are saved, tagged, or shared regularly.
ProtonMail and other encrypted services often limit exporting of email for privacy reasons. These clients may require downloading a decrypted version or using specific export tools. Be sure to respect encryption policies and only attach messages where content is meant to be shared externally.
In any alternative client, the fallback method is to manually save the email in a universal format like PDF. Then, attach it to a new message. This ensures recipients can open it without compatibility issues.
As a reference for broader email attachment knowledge, the Email attachment entry provides useful context on how different formats work across clients.
Attaching Multiple Emails in a Single Message
When you’re dealing with a series of related emails; say for a project update or a support issue; attaching them all in one message can help consolidate context for the recipient. Most desktop clients support attaching multiple emails at once through drag-and-drop or multi-selection.
In Outlook (desktop), hold Ctrl or Cmd while selecting the emails you want to attach. Then drag them into a new message window. All selected emails appear as individual attachments. They retain their original format and metadata, which allows the recipient to open each email separately.
In Gmail (web), this is a bit more manual. You must download each email as an EML file, then attach all of them to a new message. While it’s slower, it still works across all platforms. It also ensures the full message, including timestamps and sender details, is preserved.
When sending multiple messages at once, it’s courteous to include a brief summary in your own message. A quick list of what each attached email covers helps the reader scan without opening each file blindly. This saves time and improves clarity; especially when sharing with clients or colleagues in fast-paced workflows.
Keep in mind the total attachment size. Some services impose a combined file limit. If you’re attaching many messages, consider zipping them into a single compressed folder.
When to Use PDF Conversion Instead of Direct Attachment
There are times when attaching an EML or MSG file isn’t ideal. This could be due to the recipient’s inability to open that format or the need to prevent message forwarding or editing. In these cases, converting the email to PDF before attaching is the better choice.
PDF files are nearly universal. Almost every device can open them, and they provide a clean, static view of the email. This format is ideal for invoices, confirmations, or statements you want archived or printed. It also ensures that embedded formatting, logos, and images appear consistently.
If you’re preparing reports or documentation for compliance or legal use, PDF is typically the preferred format. It shows the message content as it appeared when sent or received and can be timestamped with your operating system or backup logs.
PDFs are also preferable in environments where email clients differ widely. If you’re working with clients or colleagues using various apps, converting to PDF ensures that everyone sees the message the same way. There’s no risk of someone saying “I can’t open this file.”
How This Boosts Productivity and Organization
Attaching emails, rather than forwarding them, creates more organized workflows. It keeps your message structure clean and your notes or comments separate from the original thread. This clarity helps your recipients act faster and keeps your inbox tidy.
For example, instead of copying and pasting the contents of three messages into one reply, you can attach each email as its own file. Then, write a short overview in your new message. This reduces confusion, saves time, and maintains data integrity. It also helps when team members need to revisit past discussions; each email is preserved in its original format.
If you’re managing multiple conversations or projects, attaching emails allows you to reference prior communication without cluttering your inbox or forwarding chains. This improves tracking and accountability. It also supports better archiving, since attached emails can be stored alongside related documents.
For people using Outlook in particular, attaching emails as files enhances categorization, search, and tagging. Combined with folders or automation, this technique makes your digital workspace cleaner and more efficient.
To build a broader system around this method, review Outlook tips. It offers smart folder structures and scheduling ideas that fit well with email attachments and advanced organization.
Common Issues and How to Resolve Them
Attaching an email to another email is usually straightforward; but not always flawless. Users often encounter roadblocks, especially when switching between devices, formats, or services. Common problems include attachment errors, unreadable file types, or missing data from the attached message.
One frequent issue is file format compatibility. If you send an EML or MSG file to someone using a webmail service like Gmail or Yahoo, they may not be able to open it without downloading and using a desktop client. In this case, converting the email to PDF is often the safer route. It ensures the message can be viewed on nearly any device without extra tools.
Another challenge arises when attachments within the original email don’t forward properly. For instance, forwarding an email as an attachment may include the message itself but exclude its images or files. This usually happens when using mobile clients or cloud-based apps that simplify formatting. Before sending, double-check that the attachments are present in the draft.
Mobile email apps often limit functionality. Many do not allow EML downloads or full message forwarding as attachments. If this is essential for your task, use the desktop version of your client, or access webmail through a browser.
Some users run into size restrictions. Email services often cap total message size; including attachments; to around 20–25MB. If your attached message has many embedded files or images, compress it into a ZIP folder or convert to PDF to reduce size.
Lastly, account-level security can block attached email files. Enterprise clients may scan MSG or EML files and flag them as unsafe. When sending to coworkers, let them know the file type in advance or share through secure internal platforms.
In all these cases, the best way to avoid problems is to test your process once. Send an attached email to yourself or a colleague and verify how it appears. That simple check ensures the recipient will get exactly what you intended.
Best Practices for Clear Email Attachment Sharing
Using attachments effectively depends not just on the technical steps; but also on communication. How you present attached emails to your recipient can affect how quickly they understand and act on your message. A few simple habits improve clarity and prevent confusion.
Start with a short explanation in your message body. Let the recipient know why you’re sending the attached email, and what they should do with it. For example, write: “Attached is the original client request. Please confirm if this aligns with our notes,” or “See attached email for full history of the support case.”
If you’re attaching multiple messages, mention that explicitly and, if possible, label them. This way, the recipient knows to expect more than one file and can process each in context.
Make sure filenames are clear. Instead of a generic “message.eml,” rename it to something meaningful like “ClientRequest_July.eml” or “InvoiceThread.pdf.” This is especially helpful when collaborating on shared documents or forwarding for record-keeping.
Avoid mixing email attachments with too many unrelated files. Keep your message clean and focused. If you’re sending an attached email for discussion, avoid cluttering the message with promotional banners, signatures, or other unrelated content.
Whenever possible, keep attachments light and relevant. If the attached email includes confidential or sensitive content, ensure the recipient is authorized to access it and remind them of any privacy policies in place.
Practicing these habits makes email attachments not only functional, but helpful and appreciated. They speed up collaboration and show respect for your recipient’s time.
Email Security and Privacy Considerations
Attaching an email to another message often includes forwarding sensitive content; like business records, internal discussions, or customer communications. For this reason, it’s important to consider how secure the method is and what steps you can take to protect data.
Always review the original message before attaching it. Emails can contain personal information, addresses, or account details that shouldn’t be shared widely. Before forwarding or attaching, remove any unnecessary sections or redact sensitive parts using PDF tools if needed.
Use secure email services with encryption. Most modern providers support encryption in transit, but attachments like EML or MSG files might not be protected if saved and forwarded outside that system. If the message contains critical content, use encrypted cloud links or send via secure platforms.
Be cautious when attaching messages from other people. Some companies restrict the external forwarding of internal communications. Always check your organization’s privacy or legal policies before sharing emails from coworkers or clients with outside parties.
Avoid attaching emails when using public Wi-Fi unless connected through a secure VPN. Transmitting unencrypted attachments over open networks can expose sensitive data to malicious interception.
It’s also smart to verify recipient details before sending. Auto-complete mistakes happen, and a misaddressed message with confidential content can create legal risk.
In general, treat email attachments with the same care you would any document. If it’s important enough to attach, it’s important enough to protect.
Final Takeaway on Email Attachment Methods
Attaching one email to another is a practical way to preserve context, improve clarity, and support collaboration. Whether you’re using Gmail, Outlook, Apple Mail, or another client, the steps are achievable with a little knowledge of formats and workflows.
You can choose between EML files, MSG files, or PDFs depending on what the recipient needs and what tools they have. Each method has strengths. EML offers full fidelity. PDF ensures compatibility. Drag-and-drop works on most desktops, while mobile often calls for workarounds or simple forwarding.
The method you choose should match your goal: clear communication, secure data sharing, or simple readability. With practice, attaching emails becomes second nature; and a key part of your productivity toolkit.
FAQs
Can I attach an email to a reply in Gmail?
Not directly from Gmail web or mobile. You’ll need to download the original email as an EML file, then attach it manually to a reply.
Why does Gmail forward instead of attach?
Gmail prioritizes forwarding to keep conversations streamlined. Direct attachment is available only through manual download and upload.
Can I attach emails on the mobile version of Outlook?
No. The Outlook mobile app lacks this function. Use the desktop app or web version for full attachment features.
How do I convert an email to EML or PDF?
Use “Download message” in Gmail or “Save As” in Outlook or Apple Mail. For PDFs, choose “Print” and select “Save as PDF.”
Are there size limits when attaching emails?
Yes. Most email services cap total size at 20–25MB. If the email includes large attachments, compress or use cloud services.
