To fix this, contact the recipient's email admin and ask them to add your email domain to their list of allowed senders. They may also have to adapt their validation mechanism to not reject your messages even if it fails. Refer them to RFC 2821 section 4.1.4 (at www.ietf.org), which states:
- An SMTP server may verify that the domain name parameter in the EHLO command actually correspond to the IP address of the client. However, the server must not refuse to accept a message for this reason if the verification fails: the information about verification failure is for logging and tracing only.
Unfortunately, Office 365 support can't help you fix these kinds of externally reported errors.
To fix the problem try one or more of the following: Make sure the SPF records at your domain registrar are properly configured. ...
To fix the problem, contact the recipient's email admin and give them the error and the name of the external email server ...
To fix the problem, try one or more of the following: Ask the sender scan their computer for viruses . Ask the sender to ...
To fix this issue, contact the recipient's email admin and ask them to work with their domain registrar (or Web host provider) ...
To fix this, contact the recipient's email admin and ask them to add your email domain to their list of allowed senders. ...
To fix this, work with your DNS hosting provider (your domain registrar, Web hosting provider, or ISP) to set up a correct ...
To fix this, you can change the delivery management setting for the group. Go to Groups . Choose the group you want to check, ...
To fix this, you need the external email address to Office 365. In the Exchange admin center, go to Contacts . Click New ...
To fix this, you need to add the external email address to Office 365. In the Exchange admin center, go to the Contacts page. ...