Best Kolab Alternatives in 2026
The top Kolab alternatives are Microsoft Exchange Online, Zimbra Collaboration and IceWarp: 15 mail server software our editors would look at instead of Kolab, in our ranking order.
Kolab: A broad open-source mail and collaboration suite for teams managing their own infrastructure. Where it falls short: self-hosted deployment requires your own infrastructure.
Switching from Kolab? For most mail server software buyers the best Kolab alternative is Microsoft Exchange Online, built for microsoft-centric business email. Zimbra Collaboration has a free plan.
Why People Look for a Kolab Alternative
- Self-hosted deployment requires your own infrastructure
- Mobile access relies on third-party apps
- Not suited to buyers seeking a managed hosted mail plan
Quick Picks by What You Need
- Best overallMicrosoft Exchange Online9.3
Microsoft-centric business email
Visit Microsoft Exchange Online - Best free optionZimbra Collaboration9.1
Has a free plan
Visit Zimbra Collaboration
All 15 Kolab Alternatives, Ranked
Advertiser disclosure: iTechGuides is reader-supported. Vendors can pay for top positions in our rankings and for a place on other products' pages, and we may earn a commission when you click some links. Bought places stand at the number bought; this page and our disclosure say so. Paying vendors may get a fuller, more detailed review from our editors, and that review can change their score. How we rank.
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Best forMicrosoft-centric business email
- Better than Kolab:
- Editor score 9.3 vs 7.8
A Microsoft-centric hosted mailbox service with Outlook, archiving, compliance, and migration tools.
9.3/10★★★★★Visit Microsoft -
Best forFull-featured open-source collaboration mail
- Better than Kolab:
- Editor score 9.1 vs 7.8
A broad open-source suite for organizations that need email, collaboration, and deployment control.
9.1/10★★★★★Visit Zimbra -
Best forHosted email plus productivity collaboration
- Better than Kolab:
- Editor score 9.0 vs 7.8
A broad hosted email suite with collaboration, migration tools, and self-hosted deployment.
9.0/10★★★★☆Visit IceWarp -
Best forOpen-source, scalable mail infrastructure
- Better than Kolab:
- Editor score 8.8 vs 7.8
A flexible self-hosted mail server with broad protocols, storage options, and deployment models.
- Antispam tools
- High availability
- IMAP/POP3 access
8.8/10★★★★☆Visit Apache James -
Best forWindows mail with perpetual licensing
- Better than Kolab:
- Editor score 8.7 vs 7.8
A Windows-focused mail server with a free core edition and expandable paid tiers.
- Mobile sync
- Webmail interface
- Antispam tools
8.7/10★★★★☆Visit MailEnable -
Best forHigh-performance IMAP and POP3 backends
- Better than Kolab:
- Editor score 8.6 vs 7.8
A focused, extensible mailbox backend for self-hosted Linux mail infrastructure.
- High availability
- IMAP/POP3 access
8.6/10★★★★☆Visit Dovecot -
Best forDocker-based mail and groupware deployments
- Better than Kolab:
- Editor score 8.5 vs 7.8
A Dockerized mail and groupware suite for teams managing their own infrastructure.
8.5/10★★★★☆Visit mailcow -
Best forEnterprise mail with Domino application integration
- Better than Kolab:
- Editor score 8.4 vs 7.8
A broad enterprise mail and application platform built around Domino integration.
- Mobile sync
- Webmail interface
- Antispam tools
8.4/10★★★★☆Visit HCL Domino -
Best forCommercial mail with webmail and groupware
- Better than Kolab:
- Editor score 8.3 vs 7.8
A commercial mail server with webmail, groupware, migration, and deployment flexibility.
8.3/10★★★★☆Visit Axigen -
Best forSmall and mid-market collaborative teams
- Better than Kolab:
- Editor score 8.2 vs 7.8
A broad mail and groupware server with flexible access and administrator controls.
8.2/10★★★★☆Visit Kerio Connect -
Best forAffordable self-hosted mail and groupware
- Better than Kolab:
- Editor score 8.1 vs 7.8
Affordable self-hosted email with webmail, groupware, migration tools, and optional enterprise support.
8.1/10★★★★☆Visit iRedMail -
Best forWindows-based managed mail servers
- Better than Kolab:
- Editor score 8.0 vs 7.8
A capable Windows mail server for organizations seeking on-premises or hosted Exchange alternatives.
- Mobile sync
- Webmail interface
- Antispam tools
8.0/10★★★★☆Visit MDaemon -
Best forTeams prioritizing collaboration alongside email
- Better than Kolab:
- Editor score 7.9 vs 7.8
A flexible email and collaboration suite with cloud and self-hosted deployment options.
- Mobile sync
- Webmail interface
- High availability
7.9/10★★★★☆Visit Open-Xchange -
Best forIntegrated mail for directory-managed teams
A broad self-hosted mail stack for teams that need integrated directory management.
- Mobile sync
- Webmail interface
- Antispam tools
7.7/10★★★★☆Visit Zentyal -
Best forAutomated personal or small-team mail hosting
A focused self-hosted mail stack for individuals and small teams managing their own email.
7.6/10★★★★☆Visit Mail-in-a-Box
Kolab Alternatives: Common Questions
What is the best alternative to Kolab?
Microsoft Exchange Online: #1 in our Mail Server Software ranking, with an editor score of 9.3 out of 10. A Microsoft-centric hosted mailbox service with Outlook, archiving, compliance, and migration tools.
Is there a free alternative to Kolab?
Yes. Zimbra Collaboration, Apache James, MailEnable, Dovecot and mailcow have a free plan or a free tier (8 of the 15 alternatives on this page).
Why do people look for Kolab alternatives?
Self-hosted deployment requires your own infrastructure; Mobile access relies on third-party apps; Not suited to buyers seeking a managed hosted mail plan.
How do I switch from Kolab?
Snapshot or back up the data and configs on your Kolab server. Create the new server with the same operating system and size, and add your SSH key. Copy the data across (rsync or your backup tool) and reinstall your apps or containers. Move the DNS records or IP references to the new server, test it, then cancel Kolab.
How to Switch from Kolab
- Snapshot or back up the data and configs on your Kolab server.
- Create the new server with the same operating system and size, and add your SSH key.
- Copy the data across (rsync or your backup tool) and reinstall your apps or containers.
- Move the DNS records or IP references to the new server, test it, then cancel Kolab.
Kolab vs Each Alternative
| # | Tool | Free plan | Paid from | Score |
|---|---|---|---|---|
| 14 | Kolab | Yes | Free | 7.8 |
| 1 | Microsoft Exchange Online | No | 9.3 | |
| 2 | Zimbra Collaboration | Yes | Free | 9.1 |
| 3 | IceWarp | No | 9.0 | |
| 4 | Apache James | Yes | Free | 8.8 |
| 5 | MailEnable | Yes | 8.7 | |
| 6 | Dovecot | Yes | Free | 8.6 |
| 7 | mailcow | Yes | Free | 8.5 |
| 8 | HCL Domino | 8.4 | ||
| 9 | Axigen | No | 8.3 | |
| 10 | Kerio Connect | No | 8.2 | |
| 11 | iRedMail | Yes | $10/user/yr | 8.1 |
| 12 | MDaemon Messaging Server | No | 8.0 | |
| 13 | Open-Xchange App Suite | 7.9 | ||
| 14 | Zentyal Mail Server | Yes | $230/yr | 7.7 |
| 15 | Mail-in-a-Box | Yes | Free | 7.6 |
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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