How to Open ZIP and RAR Attachments from Email

Mail apps are good at showing you that a ZIP or RAR arrived and bad at unpacking it. The preview pane, the phone share sheet and the "download anyway" banner each do a different job. If you treat the preview as the extraction, you either see nothing or you hand the file to a website you did not choose. Save the attachment into a folder you can point a local tool at, then open that saved file.

Updated 2026-10-22 · Written and tested by the UnpackNest editorial team (TECCONET)

Save first, extract second

Every major mail service stores the attachment apart from the message body. The paperclip is a pointer until you download it. Extraction needs the bytes.

1. Open the message on a computer or in a full mail app, not only in a notification.
2. Use Download, Save, or Save to Files. Avoid Open, which may launch a helper you did not mean to trust with the whole file.
3. Note the saved size. If the message quoted 8 MB and the file is 12 KB, you saved an error or a placeholder.
4. Only then open the ZIP tool or the RAR tool and pick the saved file. Do not drag the message itself onto the page. A .eml is not an archive.

This order matters on phones even more, because "Open" often uploads the attachment to whatever app won the share sheet.

Gmail on the web and on Android

In a desktop browser, hover the attachment chip at the bottom of the message and choose Download. The file goes to your browser's download folder. Gmail's own preview can show a few images inside a simple ZIP and will not list a RAR usefully. Close the preview and use the downloaded file.

Large Gmail messages sometimes arrive as a drive link ("This message is too big"). The link is not the ZIP. Open the link, download the real file, and check you are in the Google account that received the mail. A link that asks you to request access, or to sign in to a domain you have never seen, is not a size limit. It is a different problem.

On the Gmail Android app, tap the attachment, then the download arrow, then open Files by Google or the UnpackNest page and pick the downloaded copy. Tapping the chip alone may only stream a preview.

Outlook and Microsoft 365

Outlook on Windows saves from the attachment's dropdown: Save As, and pick a folder that is not a temporary Outlook cache. Files opened straight from Outlook sometimes live under a hidden Content.Outlook path that disappears when the message closes. If a helper says the archive is corrupt only when launched from Outlook, save a copy to Documents and try that copy.

Outlook on the web blocks some extensions and shows a banner. A blocked .exe renamed to .zip may still be blocked, or it may sail through. If Outlook refuses the file, that refusal is information. Do not forward it to a personal account just to defeat the banner unless you know the sender and the file.

The Outlook mobile app downloads into its own sandbox. Use the share sheet's Save to Files (iOS) or the download notification (Android) so a browser can see the file.

Apple Mail on Mac and iPhone

On a Mac, drag the attachment from the message onto the Desktop. That drag is a real copy. Double-clicking a ZIP in Mail uses Archive Utility, which is fine for ZIP and useless for RAR. For RAR, take the Desktop copy to the browser tool or to a Mac app you installed on purpose.

On iPhone, Mail does not always show a download button. Touch and hold, Share, Save to Files, then follow the iPhone RAR guide if the file is a RAR, or the ZIP guide if it is a ZIP. iCloud may keep the message attachment in the cloud until that save finishes. Wait for the size to match.

Webmail previews are not a list of files

A preview that shows the first image, or a spinning icon, has not checked CRC sums and has not applied path-safety rules. It also may have uploaded the file to the mail provider's preview service, which is a different privacy story from reading it locally. For anything other than a casual photo ZIP, download and use a tool whose behaviour you can check. The privacy guide shows the network-panel test.

Encrypted attachments and S/MIME are another layer. If the message itself is encrypted, the mail app must decrypt it before an attachment exists. A tool cannot open "the ZIP inside an unreadable message". Unlock the message with the mail client first.

Size limits, split mail, and link drops

Providers cap attachments. Gmail is often cited around 25 MB. When the sender's file is larger, you will see one of three patterns: a cloud link, several messages with part1 and part2, or a bounce you never received. Links should be downloaded in full. Parts should be gathered with the multi-part guide before anyone declares the RAR broken. A bounce means you do not have the file, no matter what the sender's outbox shows.

Some gateways wrap the original ZIP in a second ZIP and add a text file about scanning. That is nesting, covered in the nested-archive guide. Open the outer ZIP, read the text file, then open the inner archive. Do not assume the outer ZIP is the document.

When the message is the problem

Pause if any of these are true, even when the download works:

• You do not know the sender, or the address is a near-miss of someone you do know.
• The note says the password is in the same email, and the content is an invoice, a delivery, or a "voicemail".
• The saved name ends in .iso, .img, .exe, .js, or .html after extraction.
• The message threatens that an account closes today.

Expected archives from a colleague, a bank portal you logged into yourself, or a software project you follow are in a different category. The safety guide lists the tricks without asking you to become a malware analyst. Your job in the mail app is only to land a complete file in a folder, or to decide not to.

After you have the file

Open it with the matching UnpackNest tool so you can see blocked entries before anything runs. Extract the document you need. Open that document from the download folder, not from inside the archive. Programs launched from a still-zipped folder on Windows fail in odd ways because their sibling files are not really on disk.

If the tool reports truncation, compare the saved size with the attachment chip's size. Mail clients sometimes claim a download finished early on a flaky connection. Download once more. Do not start repair on the first short copy.

Frequently asked questions

Gmail shows the ZIP but Download is greyed out

The account's administrator, or Google's own type block, refused it. The grey button will not start working if you refresh. Ask the sender for a shared drive link to a plain ZIP, or download on an account that is allowed to receive it. Do not ask them to rename an executable to .zip unless you already trust the file.

I replied to the email and attached the archive again for support

Delete that habit. Support does not need the file to explain an error code, and the archive may be exactly the thing that should not be copied into another mailbox. Quote the error and the size.

The attachment is winmail.dat

That is Outlook's TNEF wrapper, not a ZIP. A normal unzip will fail. Ask the sender to resend using "plain text" or to attach the ZIP directly. Unpacking winmail.dat is a mail-format problem, and the file inside might then be a normal ZIP you can bring here.

Can I extract straight from the Gmail tab?

Only after Download has written a file. Point the tool at that file. The message view does not hand the bytes to the page, and granting a mail tab broad disk access is not a step UnpackNest asks for.

Related guides

• Archive Safety: How to Open ZIP, RAR and 7z Files Without Getting Malware
• How to Open a RAR File on iPhone and iPad
• How to Open a RAR File on Android in Your Browser
• Is Extracting Archives in the Browser Private? How to Check It Yourself