550 relaying denied office 365. 1 relaying denied” or “550 5. Apr 10, 2025 · How can I fix “550 5. Can you check and confirm if this issue is with just a specific set of users or multiple users. Try sending a test email and check if internal emails work just fine. The connector is configured for static IP address authentication, which works fine. If the issue is only with External emails in that case DBEB could possibly be blocking the emails. When I try to send mail Jun 25, 2025 · Fixes an issue that occurs when a sender uses an external email server whose IP address was added to a blocklist. Your message was routed to the wrong email server. If its is with a specific set of users. 64 TenantAttribution; Relay Access Denied SMTP bounce backs for external emails being relayed out through Microsoft 365. (Office 365) Status Code: 550 Email communication remains an essential part of both personal and professional interactions. Jun 25, 2025 · Your domain isn't fully enrolled in Microsoft 365 or Office 365 If your domain isn't fully enrolled in Microsoft 365 or Office 365, try the following steps: Verify your domain appears as Healthy in the Microsoft 365 admin center at Settings > Domains. If Internal emails don't work check the email address and proxy address attributes. 1 command rejected”? These are fixed by email authentication (SPF, DKIM, DMARC) on your domain as well as making sure you’re trying to send from a whitelisted IP/domain. May 26, 2025 · Outlook Sender Not Authorized For Relay. 1 You might see this error if: You don't have permission to send to the recipient. I guess the relaying denied bounce back message may contain the sending IP address from O365. NOTE: If you have already attempted to force the replication of mail flow settings by re-running the connection wizard and have waited for several hours for the replication to take place and are still seeing the ERROR: 550 5. 367” on Office365 Ask Question Asked 1 year, 9 months ago Modified 1 year, 4 months ago Aug 26, 2022 · Views Activity Bouncebacks: The response from the remote server was: 550 5. Apr 15, 2025 · Understand what causes '550 relaying denied' bounce errors and learn how to diagnose and resolve them, focusing on authentication, DNS, and server configuration. You don't have permission to send to the distribution group or subgroups. Result is, Relay access denied errors. . Nov 12, 2018 · In that case, your connector couldn’t identify and relay your messages to external recipients. 64 Relay Access Denied ATTR36 Jul 2, 2024 · February 27, 2018 550 5. If it did they could then compare it to what the sending IP address normally is by looking at the headers of a message successfully received by an external email address. With the rise of cloud-based services, platforms like Microsoft Office 365 have become the go-to solution for many organizations, providing robust email services alongside collaboration tools. This can be done from Exchange Admin center > Mail flow > Connectors. We are having occasional email delivery issues when an external sender sends email to our domain and the sender is getting a "550 5. 64) Software & Applications general-saas-cloud-computing , microsoft-office-365 Explains how to resolve relay-prohibited errors in an Outlook account. How we fix? In-order to relay emails externally, we’ll add the user’s IP address in the Allowed list of Receive connectors. When sending emails from a Microsoft 365 email account, you may sometimes receive a bounce-back email that reports that you are "not authorized to relay Office 365 email delivery error 5. Jan 3, 2019 · I redirect outgoing emails in my organization to my postfix MTA. 7. 64 TenantAttribution; Relay Access Denied SMTP) Software & Applications email , microsoft-office-365 , team-collaboration Jun 25, 2025 · 550 5. Explains how to resolve relay-prohibited errors in an Outlook account. 64 TenantAttribution Relay Access Denied Software & Applications microsoft-exchange , general-saas-cloud-computing , microsoft-office-365 , question 4 3353 September 5, 2022 IIS SMTP Relay to Office 365 - Relay Access Denied (550. You don't have permission to send email through an email server that's between you and the recipient. 5. Try Jun 9, 2017 · Explains one reason why external emails from or to Microsoft 365 is rejected. from there, i'm redirecting the mails to office 365 for relaying to the original recipients. However, users may encounter various Jan 19, 2024 · Emails getting a “Relay Error 550 5. 1 Relaying denied" error (in a delivery failure status notification back to them). 64 Software & Applications general-saas-cloud-computing , microsoft-office-365 , question 15 690 December 18, 2019 Microsoft SMTP Relay (550 5. For external recipients, I get the fol Jul 20, 2017 · I've configured a postfix as open relay to shove mails to an Office 365 SMTP Connector. f1 9s 2by1scrm cq5zb jusei syx rsbv dak xt nhx5y