Mail errors · Microsoft 365 and Outlook

What does “5.7.512 Access denied, message must be RFC 5322 section 3.6.2 compliant” mean?

The message had no valid From address.

Last read from the sources at the foot of this page.

Check my firm Read the steps
Microsoft bounce
Microsoft Outlook
5.7.512

Access denied, message must be RFC 5322 section 3.6.2 compliant

As Microsoft prints it.
01

What does it mean?

Every message needs a From address in the standard format. Without it, Microsoft refuses the message.

02

What exactly does the source say?

5.7.512 Access denied, message must be RFC 5322 section 3.6.2 compliant Message was sent without a valid "From" email address. Office 365 only. Each message must contain a valid email address in the "From" header field. Proper formatting of this address includes angle brackets around the email address. For example: <[email protected]>. Without an address in this format, Microsoft 365 or Office 365 rejects the message.

03

Why would a small firm see it?

A website form or a device with an empty or badly written From setting.

04

How do I fix it?

  1. Find what sent the message.
  2. Set its From address to one real address at your domain.
Sources

Where does this come from?

Related
06 · Check my firm

See what is open before anyone else does.

We read from outside, find each way in first, and show it with a check anyone can re-run. No access, nothing tested, no obligation.

What we readPublic sources only
Who sees itYou alone
Delivery72 hours from confirmation
Meeting firstNone
Reading requestPrivate
Problem: Enter your firm's name.
Problem: Enter your name.
Problem: Enter a full address, like [email protected].
Problem: That does not look like a website. Try yourdomain.com.

A person reads every request. Your outside reading comes by email within 72 hours from [email protected]. Privacy