Merchant emails bouncing back as undeliverable

[tleah1]

We are using Miva for a checkout cart only, not as our mail store. When an order is placed we have always received an email notification. Today instead of the email notifications we are getting undeliverable emails like this for each order:
This is the mail system at host web028.mivamerchant.net.

I'm sorry to have to inform you that your message could not be delivered to
one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can delete your own
text from the attached returned message.

The mail system

<[email protected]>: host dataq.com[64.64.7.122] said: 550-"JunkMail
rejected
- web028.mivamerchant.net [199.48.232.75]:32934 is in an 550 RBL:
https://www.spamhaus.org/query/ip/199.48.232.75" (in reply to RCPT TO
command)

[ILoveHostasaurus]

That's something which would need to be brought to the attention of our technical assistance center.

[tleah1]

How do I contact the technical assistance center?

[lesliekirk]

How do I contact the technical assistance center?

Send an email to [email protected]

[ILoveHostasaurus]

Email to [email protected], telephone to 800-608-6482, or support ticket via https://www.miva.com/support Email or web-based ticket would be best since they'll need to see the error.