I have recently sent several messages to an iinet.net.au email address I use regularly, and they are bouncing with the following message:
all hosts for 'iinet.net.au' have been failing for a long time (and retry time not reached).
I have sent the same person messages from my cell phone (not using Optus), and they arrive.
The same thing happened with an email sent to a netspace.net.au address.
Why do they fail when sent via Optus NBN? Has Optus got something against domains that end in .net.au?
I ran these two commands
> set type=mx
Reponds with "asav.iinet.net.au"
telnet asav.iinet.net.au 25
554-icp-osb-irony-in14.iinet.net.au 554 Your access to this mail system from 18.104.22.168 has been rejected due to the sending MTA's poor reputation. If you believe that this failure is in error, please contact the intended recipient via alternate means. Connection to host lost.
which fits with what I guessed would be happening. Optus has been added to some mail server poor reputation list. Why? Someone on the optus network has been spamming, and as a result the entire optus mailserver has been badly rated in a mail rating system somewhere. These rating systems are sometimes dodgy - they can demand money to remove your mailserver from their "bad" list.
Probably get resolved soon. Google for mail server RBL to learn more if interested.
Update: my test wasn't ideal because i was connecting from own dynamic ip not mail.optusnet.com.au .
So I sent an email to test @ iinet.net.au via optus but have received nothing back as yet. Probably stuck in the retry system, which can take a day to move out of.
If you open up your bounce message you might see more in the headers (via Properties in Outlook).
Hi @hvorrath, are you able to send email directly through → Webmail. If you are then it could be some settings in your email application. If not then I would recommend some → basic troubleshooting first.
If the issue still continues then you are best to speak with our Technical Support team either via the → messaging service or by calling them on 131344 - Mon - Fri: 8am - 8pm Sat: 9am - 5pm AEST to assist you further.