SMTP 550 5.7.705. indicates a refusal of, or shipment related to a threshold or restriction applied to. holding Microsoft 365.. Before attempting to bypass the lock, check recent volumes, compromised accounts, connectors and security alerts that may explain the protection activation.
What does this error mean?
Microsoft 365 limits the sending after exceeding,a threshold or abnormal behavior.
Probable causes
This code should not be treated by simply increasing attempts or changing the connector at random. If the threshold results from, abusion or compromise, bypassing the protection can prolong the incident.First correct the cause, secure the accounts and remove the unauthorized sending mechanisms before requesting a reassessment of the blockage.
Verification and resolution
For:. SMTP 550 5.7.705., keep the full NDR and the hour, then check the service status, security alerts and abnormal shipping activities of the. Having.. Look for recently compromised accounts, transfer rules, applications or connectors created without justification and outgoing message spikes.Try whether the rejection affects all senders or only part of the stream.
How to validate the correction — SMTP 550 5.7.705 — Holding ¥††.
After remediation, test a small volume of legitimate messages and monitor the new NDRs. If the restriction persists while the holder is assaini, gather the message identifiers, the time and actions already carried out for Microsoft 365 support.Validation must include the absence of any suspicious new activity, not just the return of the shipment.
FAQ — SMTP 550 5.7.705 — Holdings.
Does code 5.7.705 necessarily indicate piracy?.
No, but abnormal activity or threshold exceedance must be seriously investigated.
Should we create a new connector?.
Not to circumvent the restriction. First check the cause and integrity of the holder.
When to contact the support?.
After having secured the accounts, checked the flows and confirmed that the restriction persists on legitimate traffic.