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Mimecast alternatives: 5 apps ranked by verified data

Facts checked Nov 8, 2026AppBreakup editorialHow we rankAll email spam filters

Top picks

Common reasons people leave Mimecast: no public pricing; quote through sales or partners, and feature set and console can be a lot for small teams. We ranked 5 alternatives by how directly each one replaces Mimecast, then by reviews, real visits and how recently each app's facts were checked against its own website. Proofpoint currently ranks first.

Quick comparison

#AppPricingVerified priceOpen sourcePlatformsVerified factsScore
1Proofpoint logoProofpointPaid—NoWeb4 of 468.8
2SpamTitan logoSpamTitanPaid—NoWeb, Self-hosted4 of 464.8
3Proxmox Mail Gateway logoProxmox Mail GatewayOpen source€540/year per hostNoSelf-hosted, Linux4 of 461.8
4Microsoft Defender for Office 365 logoMicrosoft Defender for Office 365Paid$2 per user/month (Plan 1, yearly)NoWeb4 of 459.4
5Barracuda Email Protection logoBarracuda Email ProtectionPaid—NoWeb4 of 457.5
  1. Proofpoint logo

    1. ProofpointTop pick

    Best for: Large organisations that want gateway or API email protection plus DLP and training from one vendor

    PaidWeb

    68.8

    score / 100

    Why switch from Mimecast

    The main enterprise rival, with both gateway and API options and a broad DLP suite.

    Pros

    • Choice of inline gateway or API deployment for Microsoft 365
    • Attachment and URL sandboxing with post-delivery removal
    • Broad suite: DMARC, DLP, awareness training and archiving

    Cons

    • Quote-only pricing with no self-serve plan
    • Built for enterprises; heavy for very small businesses
    • Many features are split across separately sold modules
    Visit Proofpoint Details and reviews
    How this score is calculated
    Editorial fit ×0.3100
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.15100
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Proofpoint a good Mimecast alternative?

    Verified facts

    4 of 4 verified
    Deployment
    API or secure email gateway
    Checked Nov 8, 2026proofpoint.com(opens source in a new tab)
    Microsoft 365
    API integration
    Checked Nov 8, 2026proofpoint.com(opens source in a new tab)
    Sandboxing
    Attachments and URLs
    Checked Nov 8, 2026proofpoint.com(opens source in a new tab)
    Supported platforms
    Microsoft 365, Google Workspace
    Checked Nov 8, 2026proofpoint.com(opens source in a new tab)
  2. SpamTitan logo

    2. SpamTitan

    Best for: IT teams and MSPs who want managed spam and phishing filtering in front of Microsoft 365 or a mail server

    PaidWeb, Self-hosted

    64.8

    score / 100

    Why switch from Mimecast

    Lighter, lower-cost cloud filtering for small businesses and MSPs.

    Pros

    • Cloud service, so there's no filtering engine to maintain
    • Sandboxing and dual antivirus for attachments
    • Adds a layer in front of Microsoft 365
    • User quarantine reports and per-domain policies

    Cons

    • No public prices; quotes only
    • Closed source, unlike SpamAssassin or Rspamd
    • Aimed at businesses and MSPs rather than individuals
    Visit SpamTitan Details and reviews
    How this score is calculated
    Editorial fit ×0.387
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.15100
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is SpamTitan a good Mimecast alternative?

    Verified facts

    4 of 4 verified
    Owner
    TitanHQ
    Checked Nov 8, 2026spamtitan.com(opens source in a new tab)
    Microsoft 365
    Integrates
    Checked Nov 8, 2026spamtitan.com(opens source in a new tab)
    Sandboxing
    Yes
    Checked Nov 8, 2026spamtitan.com(opens source in a new tab)
    Pricing
    By quote
    Checked Nov 8, 2026spamtitan.com(opens source in a new tab)
  3. Proxmox Mail Gateway logo

    3. Proxmox Mail Gateway

    Best for: Companies running their own mail servers who want a packaged filtering gateway with a web UI

    Open sourceSelf-hosted, Linux

    61.8

    score / 100

    Why switch from Mimecast

    Self-hosted open-source gateway if you'd rather run filtering on your own servers.

    Pros

    • Complete gateway with web UI, quarantine and mail tracking
    • Bundles ClamAV antivirus and SpamAssassin
    • Open source and usable without a subscription
    • Subscriptions cover unlimited users and domains per host

    Cons

    • You run and maintain the gateway yourself
    • Support and the enterprise repository need a paid subscription
    • Relies on SpamAssassin, so it inherits its performance limits
    Visit Proxmox Mail Gateway Details and reviews
    How this score is calculated
    Editorial fit ×0.377
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.15100
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Proxmox Mail Gateway a good Mimecast alternative?

    Verified facts

    4 of 4 verified
    License
    GNU AGPLv3
    Checked Nov 8, 2026proxmox.com(opens source in a new tab)
    Starting price
    €540/year per host
    Checked Nov 8, 2026proxmox.com(opens source in a new tab)
    Users and domains
    Unlimited per subscription
    Checked Nov 8, 2026proxmox.com(opens source in a new tab)
    Filtering engines
    Postfix, ClamAV, SpamAssassin
    Checked Nov 8, 2026proxmox.com(opens source in a new tab)
  4. Microsoft Defender for Office 365 logo

    4. Microsoft Defender for Office 365

    Best for: Organisations on Microsoft 365 that want stronger email security without another vendor.

    PaidWeb

    59.4

    score / 100

    Why switch from Mimecast

    Already included in many Microsoft 365 plans, so a Microsoft shop may be paying for it while also paying for Mimecast.

    Pros

    • Already included in Business Premium and E5 licences
    • Covers Teams, SharePoint and OneDrive, not just email
    • Plan 2 links into Defender XDR for incident response
    • No MX record changes since it's built into Exchange Online

    Cons

    • Only protects Microsoft 365 mailboxes
    • Investigation and simulation tools need Plan 2
    • Annual per-user billing for the add-on
    Visit Microsoft Defender for Office 365 Details and reviews
    How this score is calculated
    Editorial fit ×0.369
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.15100
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Microsoft Defender for Office 365 a good Mimecast alternative?

    Verified facts

    4 of 4 verified
    Starting price
    $2 per user/month (Plan 1, yearly)
    Checked Nov 8, 2026microsoft.com(opens source in a new tab)
    Plan 2 price
    $5 per user/month (yearly)
    Checked Nov 8, 2026microsoft.com(opens source in a new tab)
    Free trial
    90 days (Plan 2)
    Checked Nov 8, 2026learn.microsoft.com(opens source in a new tab)
    Included in
    Microsoft 365 Business Premium, E3 (Plan 1), E5 (Plan 2)
    Checked Nov 8, 2026learn.microsoft.com(opens source in a new tab)
  5. Barracuda Email Protection logo

    5. Barracuda Email Protection

    Best for: Mid-sized organisations and MSPs wanting email security, archiving and Microsoft 365 backup in one.

    PaidWeb

    57.5

    score / 100

    Why switch from Mimecast

    Connects to Microsoft 365 or Google Workspace by API with no MX change, and bundles backup and archiving.

    Pros

    • API connection to Microsoft 365 and Google Workspace with no MX change
    • Bundles archiving and Microsoft 365 backup
    • Rechecks delivered mail and removes threats later
    • MSP-friendly plans and management

    Cons

    • No public per-user prices on the product page
    • Many separate modules make plans harder to compare
    • More than a small team needs for basic spam filtering
    Visit Barracuda Email Protection Details and reviews
    How this score is calculated
    Editorial fit ×0.363
    Reviews ×0.363
    Clicks (90 days) ×0.150
    Freshness ×0.15100
    Votes ×0.150

    0 counted reviews, 0 up and 0 down votes. Full formula

    Is Barracuda Email Protection a good Mimecast alternative?

    Verified facts

    4 of 4 verified
    Deployment
    API connection, no MX change
    Checked Nov 8, 2026barracuda.com(opens source in a new tab)
    Customers
    80,000+ organisations
    Checked Nov 8, 2026barracuda.com(opens source in a new tab)
    Microsoft 365 backup
    Included in bundle
    Checked Nov 8, 2026barracuda.com(opens source in a new tab)
    Platforms protected
    Microsoft 365, Google Workspace
    Checked Nov 8, 2026barracuda.com(opens source in a new tab)

The best Mimecast alternative for…

The highest-ranked app in this list for each need.

Proofpoint logo

Best Mimecast alternative for most people

Proofpoint

The main enterprise rival, with both gateway and API options and a broad DLP suite.

Proxmox Mail Gateway logo

Best Mimecast alternative for a free option

Proxmox Mail Gateway

Self-hosted open-source gateway if you'd rather run filtering on your own servers.

Proxmox Mail Gateway logo

Best Mimecast alternative for Linux

Proxmox Mail Gateway

Self-hosted open-source gateway if you'd rather run filtering on your own servers.

SpamTitan logo

Best Mimecast alternative for working in the browser

SpamTitan

Lighter, lower-cost cloud filtering for small businesses and MSPs.

Mimecast alternatives: common questions

What is the best alternative to Mimecast?

Proofpoint ranks first right now. The main enterprise rival, with both gateway and API options and a broad DLP suite. SpamTitan and Proxmox Mail Gateway follow it in our ranking.

Mimecast vs Proofpoint: what's the difference?

Both Mimecast and Proofpoint are paid products. Both run on Web.

Is Mimecast free?

Mimecast is a paid product.

How much do Mimecast alternatives cost?

Verified prices for the top-ranked Mimecast alternatives: Proxmox Mail Gateway, €540/year per host; Microsoft Defender for Office 365, $2 per user/month (Plan 1, yearly). Each price was checked on the app's own site; see each card below for the date and source.

Is there a free alternative to Mimecast?

Yes. Proxmox Mail Gateway (open source) has a free option. Check each app's verified facts for current plan limits.

Is there an open-source alternative to Mimecast?

None of the 5 alternatives in this list is open source.

Which Mimecast alternatives work on Linux?

Proxmox Mail Gateway runs on Linux.

Why do people switch from Mimecast?

The complaints we hear most: no public pricing; quote through sales or partners; feature set and console can be a lot for small teams; advanced modules cost extra on top of core filtering.

How is this list ranked?

Every app is scored with the same published formula: how directly it replaces Mimecast, reviews (weighted by verification), visits from AppBreakup, how recently its facts were checked against its own website, and reader votes.