Email attachments — photos, documents, PDFs — are something almost everyone deals with regularly. But they do not always open without a fight. Here is a plain-English guide to what to do when an attachment refuses to open, or when you cannot figure out how to send one.
Why an Attachment Will Not Open
The most common reason an attachment will not open is that your device does not have the right app to handle that type of file. Every file has a format — indicated by the letters after the dot in the filename, like .pdf, .docx, or .xlsx. Your device needs a matching app to open each type.
- .pdf — needs a PDF reader. iPhones and Android phones open these automatically. On Windows, try opening it in a web browser. On a Mac, double-click it and it opens in Preview.
- .docx or .doc — Microsoft Word documents. If you do not have Word installed, you can open these in a free word processor.
- .xlsx — Excel spreadsheets. Same situation — a free spreadsheet program can open these if you do not have Excel.
- .heic — a photo format iPhones use. Windows computers sometimes struggle with these. If you cannot open a .heic photo, first try your phone’s own sharing or camera format options, which may save or convert photos into a format your computer can open. Names and places vary by device and version. If you use a website to convert the photo, the photo is uploaded to that site, so only use a trusted converter.
The Attachment Is There but Will Not Download
If you can see the attachment in the email but clicking it does nothing, try these steps:
- Check your internet connection — attachments need to download before they open.
- Try opening the email in a web browser instead of an app. Go to your email provider’s website and try from there. The attachment should be available to open or download from there.
- If the attachment is very large (over 25MB is common), the sender may need to use a file-sharing service instead of attaching it directly.
How to Send an Attachment
On most email apps and websites, composing a new email shows a paperclip icon somewhere near the text area. Clicking or tapping this opens your files so you can choose what to attach. Once you choose a file, it should appear in the message as an attachment before you send it. On a phone, you may also see an option to add a photo directly from your camera roll.
If the file is too big to attach — most email services cap attachments at 25MB — you will usually get a warning. The solution is to share the file through a file-sharing service and paste the link into your email instead.
Is It Safe to Open?
Trust in the sender is not enough on its own, so be cautious about attachments in unexpected emails. Accounts can be taken over, and scammers can copy the names of people and companies you trust. If an attachment is unexpected, even from a known sender, check with them another way, such as a call or a separate message, before you open it. The riskiest file types are .exe, .zip, and .js — if you receive one of these unexpectedly, do not open it. PDFs can carry harmful links, so treat them with care, even when they come from someone you know. Be wary of urgent invoices or requests to pay. Do not click “enable editing” or “enable content” on a file you were not expecting.
Stop and get help if a file will not open in any app, or if it keeps failing to download. Ask the sender to confirm they meant to send it, or to send it another way. If the email came through a work account, check with your work IT team before you open repeated or unexplained attachments.
Attachment problems are almost always solvable with the right app or a quick format conversion. The key is knowing what type of file you are dealing with — once you know that, finding the right tool to open it is straightforward.
Last updated: October 9, 2026