The Office 365 sender support form is located at sender.office.com. Access requires a Microsoft account. The portal provides tools and information to troubleshoot deliverability. If an IP is blocked, the delist portal within sender.office.com can be used. Monitor sender reputation with Microsoft's SNDS and JMRP. External tools, like MXToolbox, check blacklists. Review SPF, DKIM, and DMARC records. Follow email deliverability best practices. Other resources are available from Mailjet, SendGrid, SparkPost and Litmus for diagnosing and resolving delivery issues.
10 marketer opinions
Finding the Office 365 sender support form involves several approaches. The primary method is to access the sender.office.com portal. Users must be logged into a Microsoft account (O365/Live/etc.) to use the form. If an IP address has been blocked, the delist portal within sender.office.com can be used. External tools like MXToolbox can help check domain and IP against blacklists. Microsoft's SNDS and JMRP programs can be used to monitor sender reputation. Additional steps include reviewing SPF, DKIM, and DMARC records, and implementing deliverability best practices.
Marketer view
Email marketer from EmailArchitect outlines general troubleshooting steps, starting with the sender.office.com portal. They advise to also review SPF, DKIM, and DMARC records.
24 May 2024 - EmailArchitect
Marketer view
Email marketer from SparkPost offers best practices such as proper authentication and list management to avoid being blocked by Office 365.
17 Oct 2023 - SparkPost
3 expert opinions
The Office 365 sender support form can be found at sender.office.com. In addition to utilizing the support form, it's crucial to monitor your sending reputation using Microsoft's Smart Network Data Services (SNDS) and Junk Mail Reporting Program (JMRP) to identify and address deliverability issues proactively.
Expert view
Expert from Email Geeks shares the correct link for O365 sender support: sender.office.com.
18 Apr 2025 - Email Geeks
Expert view
Expert from Email Geeks provides the context for the sender support link form.
1 May 2022 - Email Geeks
4 technical articles
Microsoft's documentation provides multiple resources for addressing Office 365 sender support. The primary Sender Support portal is located at sender.office.com, offering tools and information for troubleshooting delivery issues. In addition, Microsoft provides guidance on troubleshooting blocked senders in Outlook, interpreting NDR error codes from Exchange Online Protection (EOP), and leveraging the Smart Network Data Services (SNDS) program to monitor IP reputation and complaint rates.
Technical article
Documentation from Microsoft Learn explains how to navigate to the Sender Support portal at sender.office.com. It outlines the tools and information available to troubleshoot delivery issues related to Office 365.
27 Jun 2021 - Microsoft Learn
Technical article
Documentation from Microsoft Learn describes how to interpret Non-Delivery Report (NDR) error codes from Exchange Online Protection (EOP). This helps diagnose specific delivery problems.
26 Dec 2023 - Microsoft Learn
How can I contact ProofPoint support to resolve email delivery issues?
How do email marketers effectively deal with Microsoft Sender Support's automated responses and email blocking issues?
How do I contact Microsoft about email deliverability issues for B2B clients?
How do I contact Yahoo Sender Support?
Where can I find the Microsoft Outlook sender support form?