How To Forward An Email With Attachments Across Gmail, Outlook, And Mobile Platforms

Forwarding an email with its attached files requires selecting the dedicated Forward command rather than Reply, as standard Internet Message Format protocols (RFC 5322) automatically strip attachment payloads during reply threads to conserve bandwidth. Successful forwarding depends on keeping the total message size below standard SMTP relay limits—typically 25 Megabytes for webmail providers—or leveraging automated cloud storage links for oversized files. Verifying media types and checking draft previews before transmission prevents attachment loss across differing desktop and mobile clients.

Prerequisites and System Payload Specifications

Before initiating an email forward containing file attachments, evaluating system constraints and client configuration prevents delivery failures. Email servers process attachments by converting binary data into ASCII text using Multipurpose Internet Mail Extensions (MIME) encoding, which increases the overall payload size by approximately 33 percent relative to the original file size on disk.

• Essential Software and Access: Active account access on a desktop web browser (Chrome, Safari, Edge, Firefox) or dedicated email desktop/mobile software (Microsoft Outlook, Apple Mail, Gmail app).
• Protocol Standards: Native support for MIME structures (multipart/mixed for distinct attached files and multipart/related for embedded inline graphics).
• Size and Security Thresholds: Individual file limits capped between 20 MB and 25 MB across standard SMTP relays, with executable extensions (.exe, .bat, .vbs, .iso) strictly filtered by inbound security gateways.
• Time and Data Estimates: Process duration requires 30 to 60 seconds per email thread; network transmission speeds depend on local uplink bandwidth (a 20 MB payload requires approximately 4 seconds on a 50 Mbps upload stream).

Mastering Email Forwarding with Attachments: Core Execution Steps

Step 1: Distinguish Between Reply and Forward Actions

Open the target communication thread within your email client interface. Locate the main action toolbar usually positioned at the top right of the message container or at the bottom of the conversation view.

Warning: Clicking "Reply" or "Reply All" creates a clean response thread that purposefully drops all existing attached documents, images, and archives. You must explicitly select the Forward command (represented by a right-facing arrow) to force the client software to clone the MIME structure and retain attached files.

Step 2: Trigger the Forward Command and Inspect Draft Generation

Click Forward. Your email client creates a new draft message. Inspect the top metadata area of the new compose pane to confirm the presence of header data (Original Sender, Date, Subject, and Recipient list) copied into the message body area.

Locate the dedicated attachment area—positioned directly below the Subject line in Outlook, at the bottom of the draft window in Gmail Web, or below the header cards in Apple Mail. Verify that every file icon, filename, and file extension match the payload of the original message.

Step 3: Manage and Modify Attached Payloads (Optional)

If you need to edit the payload list prior to sending, manage individual files directly within the draft view:

1. Hover over the unwanted file card inside the draft compose box.
2. Click the X, trash icon, or right-click and select Remove Attachment to drop specific files while leaving others intact.
3. Drag and drop supplemental documents directly into the compose interface if additional contextual files are required for the new recipient.

Pro-Tip: If you need to retain attachments while removing sensitive historical context from the lower email thread, delete the text inside the lower body area manually. Stripping the historical text body does not detach files already registered in the draft payload field.

Step 4: Handle Large Payload Transmissions

If the total file footprint exceeds server parameters (e.g., forwarding a 40 MB media folder), select the client’s native cloud hosting workaround rather than transmitting raw binary attachments:

1. Save the original attachments to your local disk or cloud drive.
2. Upload the files to Google Drive, Microsoft OneDrive, or iCloud.
3. Set appropriate audience access permissions (e.g., "Anyone with the link can view").
4. Remove the heavy native attachments from the forwarded draft and paste the shared cloud URI into the message body.

Step 5: Address and Dispatch the Message

Type the destination email addresses into the To, Cc (Carbon Copy), or Bcc (Blind Carbon Copy) address input fields. Add any clarifying notes or instructions above the automatically generated ----- Forwarded Message ----- delimiter bar. Perform a final review of the attachment cards, then click Send.

Email Client Specifications and Attachment Limits

The following table details the baseline operational rules, payload capacities, and cloud integration behavior across primary mail user agents when forwarding messages with attachments.

Resolving Common Email Forwarding and Attachment Failures

Missing Attachments in Forwarded Messages

• Root Cause: The user accidentally selected "Reply" or "Reply All" instead of "Forward," or the client is configured to render messages in Plain Text mode, stripping complex MIME structures. Alternatively, the original email contained inline web-hosted images () rather than actual binary attachments, causing external resources to fail to load on external networks.
• Actionable Fix: Re-open the original message, verify that actual file cards exist, and explicitly click Forward. If using Microsoft Outlook Desktop, open File > Options > Mail, navigate to the Message format section, and ensure "When forwarding a message" is set to HTML or Rich Text instead of Plain Text.

Delivery Rejection Notice: 552 5.3.4 or Message Size Exceeded

• Root Cause: The cumulative size of the original message body, historical text, and forwarded files exceeds the receiving mail transfer agent's (MTA) maximum inbound transaction threshold.
• Actionable Fix: Save the attachments to your local storage device. Compress large documents into a single compressed .zip archive (ensuring no restricted script files exist inside). If the archive still exceeds 20 MB, upload the files to a cloud storage system (Google Drive, OneDrive, Dropbox), delete the attached files from the forwarded draft, and insert the cloud download URL directly into the body text.

Files Replaced by a Single Winmail.dat File

• Root Cause: Microsoft Outlook transmitted the email using the proprietary Transport Neutral Encapsulation Format (TNEF). Non-Outlook receiving clients (such as Gmail, Apple Mail, or Thunderbird) cannot parse TNEF payloads, collapsing all inline content and attachments into an unreadable winmail.dat binary file.
• Actionable Fix: In Outlook Desktop, navigate to File > Options > Mail. Scroll down to the Compose messages section and set "Compose messages in this format" to HTML. Scroll further down to Message format and change "When sending messages in Rich Text format to Internet recipients" to Convert to HTML format. Re-forward the email to the recipient.

Security Gateway Blocking Specific File Extensions

• Root Cause: The recipient’s organizational security filter (such as Mimecast, Proofpoint, or Microsoft Defender for Office 365) flagged the forwarded attachment due to potentially dangerous file extensions or password-protected archives.
• Actionable Fix: Extract the payload from the original email and inspect its contents. If forwarding scripts or executable files for legitimate software distribution, host the files within an authenticated enterprise repository and send an access-controlled link. If forwarding password-protected .zip files, communicate the decryption key via an out-of-band communication channel (e.g., messaging apps or phone call) rather than including it in the forwarded body text.

Frequently Asked Questions

Does forwarding an email automatically include the original attachment?

Yes, using the standard Forward function automatically clones all attached files into the newly created draft message across all major email clients. Selecting Reply or Reply All strips attached files by default to limit redundant server bandwidth usage.

Why did the attachment disappear when I forwarded an email on my mobile phone?

Mobile email apps often download only the text header and body of an email to save cellular data, leaving the physical attachment on the mail server until requested. If you forward the message before the attachment has fully downloaded to your device cache, the app may forward only the text portion. Ensure the attachment preview icon fully loads on your screen before tapping the Forward button.

How do I forward an email body without including its original attachments?

Click Forward to generate the draft message, then locate the attachment container area in the compose window. Click the Remove, Delete, or X icon next to each listed file to clear them from the payload before entering the recipient's address and clicking Send.

Can I forward multiple emails containing attachments at the same time?

Yes. In desktop applications like Microsoft Outlook or Apple Mail, highlight multiple messages in your inbox list while holding the Ctrl key (Windows) or Command key (Mac). Click Forward in the main ribbon to generate a single new draft that bundles all selected emails and their respective attachments into a consolidated message or as attached .eml files.

What happens to inline images when an email is forwarded?

Inline images categorized as multipart/related MIME objects remain embedded in the HTML body of the message when forwarded, provided your client is configured to compose messages in HTML format. If converted to Plain Text during the forward process, inline images are either removed entirely or converted into standard file attachments at the bottom of the email.

Optimize Your Corporate Mail Workflow

Implementing precise message forwarding standards keeps cross-organizational communications secure, reliable, and compliant with network protocol parameters. For enterprise systems engineering and IT infrastructure management, implementing automated email routing rules and file payload security controls ensures seamless file distribution without overloading mail server architecture. Configure your organization's messaging policies to leverage cloud offloading integrations for high-volume file transfers.