<a href="https://www.lifewire.com/yahoo-tips-tricks-4102594" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="1">Yahoo! Mail</a> automatically checks any file you send (or receive) as an attachment for known viruses. When you are really short of ideas what to do next with your computer, you can use this feature to scan your files for viruses, one by one.<h3>Use Yahoo! Mail as a Virus Scanner</h3><p>To use Yahoo! Mail as a virus scanner:</p><ul><li>Create a new email message in Yahoo! Mail. </li><li>Start <a href="https://www.lifewire.com/send-attachment-yahoo-1174490" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="2">attaching your files</a>. </li><li>Be sure to remove the files immediately after attaching them. </li></ul><p>You <a href="https://www.lifewire.com/attachment-message-size-limits-yahoo-1174505" data-component="link" data-source="inlineLink" data-type="internalLink" data-ordinal="3">cannot scan files larger than 10 MB in Yahoo! Mail (20 MB in Yahoo! Mail Plus)</a>.</p><p>Yahoo! Mail Classic only allows three attachments per message. And be aware that the process of scanning your files can take a very long time. Every file must be uploaded to Yahoo&#39;s servers before it can be scanned. You cannot scan files bigger than 1.5 MB in Yahoo! Mail Classic.</p>