Best OpenSMTPD Alternatives in 2026
The top OpenSMTPD alternatives are Microsoft Exchange Online, Zimbra Collaboration and IceWarp: 15 mail server software our editors would look at instead of OpenSMTPD, in our ranking order.
OpenSMTPD: A focused SMTP server for self-hosted mail routing, relay, and delivery. Where it falls short: does not provide a webmail interface.
Switching from OpenSMTPD? For most mail server software buyers the best OpenSMTPD alternative is Microsoft Exchange Online, built for microsoft-centric business email. Zimbra Collaboration has a free plan.
Why People Look for an OpenSMTPD Alternative
- Does not provide a webmail interface
- Does not include IMAP or POP3 mailbox access
- Lacks mobile synchronization and high availability
- No webmail interface — 5 of the alternatives below have it
- No iMAP/POP3 access — 7 of the alternatives below have it
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 - Best for webmail interfaceMailEnable8.7
Webmail interface (OpenSMTPD: no)
Visit MailEnable
All 15 OpenSMTPD 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 OpenSMTPD:
- Editor score 9.3 vs 6.2
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 OpenSMTPD:
- Editor score 9.1 vs 6.2
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 OpenSMTPD:
- Editor score 9.0 vs 6.2
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 OpenSMTPD:
- IMAP/POP3 access
- Editor score 8.8 vs 6.2
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 OpenSMTPD:
- Webmail interface
- IMAP/POP3 access
- Mobile sync
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 OpenSMTPD:
- IMAP/POP3 access
- Editor score 8.6 vs 6.2
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 OpenSMTPD:
- Editor score 8.5 vs 6.2
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 OpenSMTPD:
- Webmail interface
- IMAP/POP3 access
- Mobile sync
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 OpenSMTPD:
- Editor score 8.3 vs 6.2
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 OpenSMTPD:
- Editor score 8.2 vs 6.2
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 OpenSMTPD:
- Editor score 8.1 vs 6.2
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 OpenSMTPD:
- Webmail interface
- IMAP/POP3 access
- Mobile sync
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 OpenSMTPD:
- Webmail interface
- IMAP/POP3 access
- Mobile sync
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 forOpen-source mail with collaboration tools
- Better than OpenSMTPD:
- Editor score 7.8 vs 6.2
A broad open-source mail and collaboration suite for teams managing their own infrastructure.
7.8/10★★★★☆Visit Kolab -
Best forIntegrated mail for directory-managed teams
- Better than OpenSMTPD:
- Webmail interface
- IMAP/POP3 access
- Mobile sync
A broad self-hosted mail stack for teams that need integrated directory management.
- Mobile sync
- Webmail interface
- Antispam tools
7.7/10★★★★☆Visit Zentyal
OpenSMTPD Alternatives: Common Questions
What is the best alternative to OpenSMTPD?
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 OpenSMTPD?
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 OpenSMTPD alternatives?
Does not provide a webmail interface; Does not include IMAP or POP3 mailbox access; Lacks mobile synchronization and high availability.
How do I switch from OpenSMTPD?
Snapshot or back up the data and configs on your OpenSMTPD 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 OpenSMTPD.
How to Switch from OpenSMTPD
- Snapshot or back up the data and configs on your OpenSMTPD 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 OpenSMTPD.
OpenSMTPD vs Each Alternative
| # | Tool | Free plan | Paid from | Score |
|---|---|---|---|---|
| 30 | OpenSMTPD | Yes | Free | 6.2 |
| 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 | Kolab | Yes | Free | 7.8 |
| 15 | Zentyal Mail Server | Yes | $230/yr | 7.7 |
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
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