emails from outlook to bigpond.net.au

The following is the error message I get when I try to email from my Outlook.com account to any bigpond.net.au or bigpond.com addresses. "Generating server: OS3P286MB1472.JPNP286.PROD.OUTLOOK.COM
Receiving server: OS3P286MB1472.JPNP286.PROD.OUTLOOK.COM

d*****@bigpond.net.au
11/22/2021 10:10:46 PM - Server at OS3P286MB1472.JPNP286.PROD.OUTLOOK.COM returned '550 5.4.317 Message expired, cannot connect to remote server(450-4.4.317 Cannot connect to remote server [Message=550-5.7.1 Connection refused - IB116. 40.92.98.45 senderscore too low. Please check https://senderscore.org [OS0JPN01FT005.eop-JPN01.prod.protection.outlook.com] 450 4.4.317 550 4.7.25 Temporarily rejected. Reverse DNS for 40.92.98.45 failed. IB108] [LastAttemptedServerName=bigpond.net.au] [LastAttemptedIP=203.36.137.234:25])'
11/22/2021 10:03:02 PM - Server at bigpond.net.au (203.36.137.234) returned '450-4.4.317 Cannot connect to remote server [Message=550-5.7.1 Connection refused - IB116. 40.92.98.45 senderscore too low. Please check https://senderscore.org [OS0JPN01FT005.eop-JPN01.prod.protection.outlook.com] 450 4.4.317 550 4.7.25 Temporarily rejected. Reverse DNS for 40.92.98.45 failed. IB108] [LastAttemptedServerName=bigpond.net.au] [LastAttemptedIP=203.36.137.234:25]'" It seems the problem is the Outlook SENDERSCORE is too low. How can this be fixed?EDIT: Removed PII.

Hi Glenn

Thanks for your response. I have just been on the phone to Telstra, who state that it isn't their problem, its a problem with Outlook email (interestingly only emails to bigpond.net.au and bigpond.com are being blocked - all other emails are getting through, including to hotmail and gmail accounts as well as emails to company email addresses).

So back to reviewing my outlook account to determine why these emails are being blocked.

regards

Kate

Emails sent using Outlook & outlook.com account (on HP Laptop, iMac & iPhone) to a family bigpond.net.au address are not getting through for last 3 days. Web-version does not appear to have this problem.

I'm not very tech so struggling with all the articles with similar messages & solutions.

Does anyone have a simple explanation/solution I could follow?

Delivery has failed to these recipients or groups:

"******@bigpond.net.au"
Your message wasn't delivered. Despite repeated attempts to deliver your message, a connection to the remote server couldn't be made.

Contact the recipient by some other means (by phone, for example) and ask them to tell their email admin that it appears that your email system is unable to connecto their email system. Give them the error details shown below. It's likely that the recipient's email admin is the only one who can fix this problem.

For more information and tips to fix this issue see this article: https://go.microsoft.com/fwlink/?LinkId=389361.

Diagnostic information for administrators:

Generating server: TYBPR01MB5533.jpnprd01.prod.outlook.com
Receiving server: TYBPR01MB5533.jpnprd01.prod.outlook.com 

"******@bigpond.net.au"
11/20/2021 1:42:45 AM - Server at TYBPR01MB5533.jpnprd01.prod.outlook.com returned '550 5.4.317 Message expired, cannot connect to remote server(421 4.7.25 Temporarily rejected. Reverse DNS for 40.92.98.107 failed. IB108)'
11/20/2021 1:36:53 AM - Server at bigpond.net.au (203.36.137.234) returned '450 4.4.317 Cannot connect to remote server [Message=421 4.7.25 Temporarily rejected. Reverse DNS for 40.92.98.107 failed. IB108] [LastAttemptedServerName=bigpond.net.au] [LastAttemptedIP=203.36.137.234:25] OS0JPN01FT008.eop-JPN01.prod.protection.outlook.com'

Hi Kate AK!

We’re glad that you’ve reached out to the Microsoft Community Forum where our members work together to address your technical support needs.

We understand that you're getting a non-delivery report (NDR) or bounce message when sending an email -- using both Outlook.com and the Outlook app -- to a bigpond.net.au email address.

The bounce message you get actually indicates that the issue is on bigpond.net.au's end and not on Microsoft's. With that in mind the owner of the bigpond.net.au email address needs to contact the email provider -- Telstra -- on how to unblock senders.

Also check with Telstra if their email servers are down since the bounce message you got indicated as much.

We look forward to your response.

Sincerely,

Glenn Rue

Consumer M365 Forum Moderator

Microsoft Community