451 4.4.1 Error code returned from exhange server

[apfund]

When sonic users send email to my Exchange 2003 server, they get the following error message:

451 4.4.1 reply: read error from oahu.apfund.com.
<someaddress@xxxxxxxxxx>... Deferred: Input/output error.

I only get this error message from a customer of sonic.net, voicemail forwarding, and fax emailing from sonic.net.

I do however receive emails from sonic support's automated messaging.

I have not had anyone else complain about me not receiving their emails.

Thanks

Alex Pfund

[kgc]

Alex, we've been investigating this problem for a couple of days. It is believed to be due to stricter cipher and/or DH params used by our mail servers per current recommendations. It is known that these changes may cause interoperability issues with older mail servers.

[apfund]

Is Sonic doing something to fix this problem, or is anyone running older servers not going to receive email from your clients? I can't be the only on having an older server. It is not in the budget to upgrade my server at this time.

[kgc]

We're not sure what the problem is yet and so I can't really answer the question. Over the past few days we've only seen two servers that seem to be affected. Have all available patches and updates have been applied to your server and all relevant software running on it?

[apfund]

Yesterday, I received a couple of messages from Sonic. I had someone who has a Sonic account send me an email, and it worked. Not sure what you did to fix the problem. Thank You.

[kgc]

We extended an existing tool that monitors our mail servers for specific SSL related errors sending mail to remote servers and then disables SSL negotiation with the affected remote hosts. This is not desirable from a security perspective.