We've recently faced an issue where emails sent from our domain are being bounced back by companies using Barracuda's email filtering service due to suspected spam. Initially, we received a few of these bounce-back notifications, leading us to investigate further. Despite reaching out to Barracuda, they directed us to the recipient companies for whitelisting since we aren't their client. Their reputation checker indicated that our domain isn't blocked or banned. We're using Exchange Online with DMARC properly configured. Has anyone else encountered a similar issue, or does anyone using Barracuda have insights on why our emails might be flagged as spam?
4 Answers
Barracuda often relies on global blocklists to filter emails, and getting off those lists can be a real hassle. I've dealt with a similar situation before, and it took a lot of effort to resolve. Have you checked if your domain is listed on any blocklists?
Are you sending out only transactional messages, or are you mixing in marketing emails too? The content type might also influence how Barracuda filters your messages.
We've also experienced some bounce-backs from Barracuda. One possibility could be malformed DNS records on the sender's end. It's worth double-checking your DMARC and other DNS settings, as misconfigurations there can definitely raise red flags.
I’ve double-checked everything, and it only seems to happen with Barracuda-related companies. I’d also love to connect with another IT pro on this!
Check your SPF record settings carefully. If you have a soft fail or overly permissive rules, it might lead to issues with email delivery.
I do have a soft fail in place, but I didn't think that would be the main issue.

We weren't listed, but it was still a headache with a client getting really frustrated about it.