Enhanced SMTP status code · RFC 3463 · IANA
4.7.500-699 Access denied, please try again later
Microsoft noticed suspicious activity and temporarily restricted sending while it evaluates it.
- Class: Temporary failure
Class 4: a persistent transient failure. The message was fine, but a passing condition delayed or stopped delivery; a later attempt may succeed (RFC 3463 §3.1). The sending server retries on its own for a while.
- Subject: X.7 · Security and policy
Policies (per-host or per-recipient filters) and cryptographic operations; up to the sender, the recipient or both.
How 4.7.500-699 appears at providers
The exact text from the provider's documentation, as you see it in the bounce, and what it means.
Microsoft 365 / Exchange Online
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4.7.500-699
Access denied, please try again later
Microsoft noticed suspicious activity and temporarily restricted sending while it evaluates it.
Have the whole error message?
Sources: RFC 5321 · RFC 3463 · RFC 3464 · IANA · Gmail · Microsoft 365 · read on 26 September 2026