Microsoft security help and learning
Get security info and tips about threat prevention, detection, and troubleshooting. Including tech support scams, phishing, and malware.
Office Help & Training
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发送电子邮件时，我收到 550、553 或中继禁止的错误 - Microsoft 支持
垃圾邮件和开放中继. 未经请求的商业电子邮件有时称为垃圾邮件或垃圾邮件。 垃圾邮件数量继续增加的main原因是，发送垃圾邮件的人几乎不需要发送任何费用;事实上，发件人甚至不必通过 SMTP (发送垃圾邮件，) 他们自己的 ISP 的电子邮件服务器发送垃圾邮件。
Applies To:
Outlook for Microsoft 365, Outlook 2021, Outlook 2019, Outlook 2016, Outlook 2013
Surface help & learning
Choose from a variety of Surface devices and accessories to get help.
Improve accessibility with the Accessibility Checker
Apply recommended actions. In the Accessibility pane, you'll see a list of errors and warnings, with how-to-fix recommendations for each.. To quickly correct the issues, apply one of the recommended actions. For more information on how the findings are categorized, see Rules for the Accessibility Checker. In the Accessibility pane, select an issue under Warnings or Errors.
Applies To:
Excel for Microsoft 365, Word for Microsoft 365, Outlook for Microsoft 365, PowerPoint for Microsoft 365, OneNote for Microsoft 365, Visio Plan 2, Excel for Microsoft 365 for Mac, Word for Microsoft 365 for Mac, Outlook for Microsoft 365 for Mac, PowerPoint for Microsoft 365 for Mac, OneNote for Microsoft 365 for Mac, Excel for the web, Word for the web, OneNote for the web, PowerPoint for the web, Excel 2021, Word 2021, Outlook 2021, PowerPoint 2021, Visio Professional 2021, Visio Standard 2021, OneNote 2021, Excel 2021 for Mac, Word 2021 for Mac, Outlook 2021 for Mac, PowerPoint 2021 for Mac, OneNote 2021 for Mac, Excel 2019, Word 2019, Outlook 2019, PowerPoint 2019, Visio Professional 2019, Visio Standard 2019, Excel 2019 for Mac, Word 2019 for Mac, Outlook 2019 for Mac, PowerPoint 2019 for Mac, OneNote 2019 for Mac, Excel 2016, Word 2016, Outlook 2016, PowerPoint 2016, OneNote 2016, Visio Professional 2016, Visio Standard 2016, Office for business, Office 365 Small Business, Microsoft 365 admin, Office 365 operated by 21Vianet, Office 365 operated by 21Vianet - Small Business Admin, Office 365 operated by 21Vianet - Admin
Microsoft Support
Microsoft support is here to help you with Microsoft products. Find how-to articles, videos, and training for Microsoft Copilot, Microsoft 365, Windows, Surface, and more.
Office Help & Training
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Microsoft PC accessories help & learning
Get expert help, training, and support for your Microsoft PC accessories with easy access to resources and guidance.
Microsoft 支援服務
Microsoft 支援服務可協助您處理 Microsoft 產品。 尋找適用於 Microsoft Copilot、Microsoft 365、Windows、Surface 等的使用方法文章、影片和訓練。
Common problems with two-step verification for a work or school account
Ensure these modes create an alert that is visible on your device. Make sure you have a device signal and Internet connection. Make sure your phone calls and text messages are getting through to your mobile device.