Should we replace Barracuda with the M365 tools we already have?

M365 can be a reasonable fit at this size, especially if your organization already pays for the relevant Defender features. But treat it as a migration and configuration project, not a simple switch. Review anti-phishing and impersonation settings, Safe Links and Safe Attachments if licensed, quarantine policies, and who can release messages.

Run a pilot before changing mail routing. Also investigate why legitimate mail is being caught. Broad domain allowlists can conceal the underlying issue, and carrying them over unchanged may create the same problem in M365.

I wouldn’t assume every Barracuda issue means the service itself is the problem. Some organizations report it works with little day-to-day attention, while others find the policy and quarantine experience frustrating. Before renewing or leaving, look closely at your own rules, message logs, and repeated false positives. If the configuration is sound and the overhead is still high, that’s useful evidence for switching.

There isn’t one obvious winner among the alternatives. Feedback on Proofpoint is mixed, including concerns about user provisioning delays. Mimecast has satisfied some teams, while others describe limited flexibility or slower mail flow. Compare the specific features, support, integration work, and total cost for your setup rather than choosing by brand reputation alone.

If you evaluate another gateway, test user onboarding and message delivery during a pilot. Those operational details can matter as much as filtering quality.

For a small IT team, I’d start with the M365 option you already own and measure how it performs before adding another product. If you still need stronger protection or workflow features, assess specialist services alongside it. Check the exact licensing first, since not every Defender feature is included in every plan.

Also compare the real cost: subscriptions, implementation, support, and the time spent managing policies. A lower invoice doesn’t help much if the new setup creates extra work.

Keep the current service in place until you’ve tested the replacement end to end. Include common legitimate senders, suspicious messages, quarantine notifications, user release permissions, and mail flow during onboarding. Have a rollback plan before making a routing change, and avoid copying broad allow rules without reviewing them.