Bounce with 5.4.1: 'recipient address rejected, access denied'
5.4.1 points to a routing or access issue at the recipient. The address may exist, but a rule or connector blocks it.
Try this first
- 1Ask the recipient to check whether your address is blocked
- 2Check transport rules in their Exchange Online tenant
- 3Send a test from a different domain to rule out a sender issue
- 4On hybrid setups: check connector routing between on-prem and cloud
When to bring us in
5.4.1 can't be fixed on the sending side if the recipient denies access, they have to look.
See also
- Our emails land in spam for some recipientsAlmost always an SPF, DKIM, or DMARC setting that is wrong or missing, or a sender name that mimics a well-known brand.
- Someone reports receiving phishing emails "from us"Read: spoofing. Someone is abusing your sender name, not necessarily your actual mailbox.
- An email bounces (NDR): delivery failedThe NDR text usually states the exact reason. Reading it is step one.
None of the above fits?
Describe your situation below. We pass your input plus the steps you already saw to our AI and return tailored next-step advice. If it's too risky to DIY, we'll say so.
Or skip the DIY entirely
Our Managed IT clients do not look these things up. One point of contact, a fixed monthly price, resolved within working hours.