Open .msg and winmail.dat files on Android

Why Android can’t open them

Outlook .msg files and winmail.dat attachments use Microsoft’s own email formats. Gmail shows them as attachments it can’t preview, and the Files app usually offers nothing to open them with. The message and its attachments are inside; Android just doesn’t have anything that reads the format.

Open one in Chrome

1. In Gmail (or your mail app), tap the download icon on the attachment so it’s saved to your Downloads folder.
2. Open this page in Chrome and tap Choose a file.
3. Pick the file from Downloads (choose Browse or the menu if you don’t see it in Recent).
4. The email appears with its sender, recipients, date and message. Tap Save next to any attachment to download it.

The page reads the file on your phone. Nothing is uploaded, and there’s no app to install or account to make.

winmail.dat attachments

If an email from an Outlook user arrives with a winmail.dat attachment instead of the files you expected, those files are inside it. Open the winmail.dat here and they appear in the attachment list. Here’s why it happens, and what the sender can change.

Tips

• Downloads usually land in the Download folder; the Files by Google app lists them under Downloads.
• If the attachment opened in another app instead of downloading, use that app’s Share or Save option to put it in Downloads first.
• Pictures in an email that come from the internet are held back until you tap Show pictures, so the sender can’t tell you opened it.

When it can’t be opened

Some emails are deliberately locked: S/MIME-encrypted messages and messages with Microsoft’s “Do not forward” protection can only be opened by the person they were sent to, in Outlook. The page tells you when that’s the case rather than showing a blank screen.

Is it safe to open on my phone?

Yes. The page treats every email as if it might be hostile. The message is shown in a sealed-off frame where scripts can’t run and forms can’t send anything, and links open in a new tab so you can see where they go first. Attachments are saved as files, never opened inside the page, and file types that can carry programs or macros are pointed out. As with any attachment, only open the saved file if you trust the sender.