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Head-to-head · Email Server Software

Synology MailPlus Server vs Mail-in-a-Box

  • Updated Oct 2026
  • Both researched from official sources
  • 5 checks side by side
Higher score Synology MailPlus Server #6 in Email Server Software 8.6/10 Free plan Free plan✓ 4 of 4 features Visit Synology
Mail-in-a-Box #8 in Email Server Software 8.4/10 Free plan Free plan✓ 0 of 4 features Visit Mail-in-a-Box

Synology MailPlus Server leads on 0 checks, Mail-in-a-Box on 0, and 5 are even. Who comes out ahead on the 5 yes/no, price and count checks where we have data for both products. The editor score weighs everything else too.

Our verdict

  • Highest scoreSynology MailPlus Server · 8.6/10
  • Free planboth
  • Most featuresSynology MailPlus Server · 4 of 4

Synology MailPlus Server scores higher on our rubric for email server software: 8.6 against 8.4 out of 10; our editors rank them #6 and #8.

Synology MailPlus Server is the better fit for synology NAS users hosting organizational email. Mail-in-a-Box is the better fit for small teams self-hosting a complete mail setup.

  • Synology MailPlus Server fits best

    Synology NAS users hosting organizational email

  • Mail-in-a-Box fits best

    Small teams self-hosting a complete mail setup

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. How we rank.

Side by side

Feature Synology MailPlus Server 8.6/10 Visit ↗ Mail-in-a-Box 8.4/10 Visit ↗
At a glance
Editor score 8.6 8.4
Ranking #6 in Email Server Software #8 in Email Server Software
Best for Synology NAS users hosting organizational email Small teams self-hosting a complete mail setup
Pricing model Free plan + paid Free
Starting price Free plan Free plan
Free plan ✓ ✓
Free trial — —
Deployment Self-hosted Cloud, Self-hosted, Browser extension
Platforms Web, iOS, Android Web, Linux
Compliance GDPR 2FA
Integrations 7 integrations 1 integrations
Built for Small business, Mid-market, Enterprise Solo, Small business
Features Synology MailPlus Server 4/4 · Mail-in-a-Box 0/4
Mail transfer agent ✓ (best) Not checked yet
Mailbox server ✓ (best) Not checked yet
Integrated mail server ✓ (best) Not checked yet
Directory integration ✓ (best) Not checked yet
Specs
Deployment Self-hosted Not checked yet
Email protocols SMTP, IMAP, POP3 Not checked yet
Our review
Pros
  • Supports SMTP, IMAP, and POP3 for mail-client access
  • Migration from Microsoft Exchange and Google Workspace
  • Directory integration, policy controls, filtering, and clustering
  • Bundles Roundcube webmail with IMAP and SMTP access.
  • Automates TLS provisioning, mail DNS setup and system health checks.
  • Control panel manages users, aliases, DNS and backups.
Cons
  • Requires compatible Synology NAS hardware and self-hosted administration
  • Only five email-account licenses are included with compatible NAS hardware
  • License packs add cost, and pricing is not published on the official page
  • Requires a dedicated machine and ongoing server administration.
  • Community is the listed support channel.
  • Listed integration is limited to Amazon S3.
Our verdict

Synology MailPlus Server turns compatible Synology NAS hardware into a self-hosted organizational email system. It suits small, mid-market, and enterprise teams that want to host custom or multiple domains and administer mail on their own…

Read the review →

Mail-in-a-Box is free, open-source software for people and small teams who want to operate their own email service. It turns a fresh cloud machine running Ubuntu into a mail server, with Roundcube webmail, IMAP and SMTP access, and contact…

Read the review →
  1. Synology MailPlus ServerEmail Server Software 8.6Free plan
  2. Mail-in-a-BoxEmail Server Software 8.4Free plan

Strengths and trade-offs

  • Synology MailPlus Server — where it wins

    • Supports SMTP, IMAP, and POP3 for mail-client access
    • Migration from Microsoft Exchange and Google Workspace
    • Directory integration, policy controls, filtering, and clustering

    Where it doesn't

    • Requires compatible Synology NAS hardware and self-hosted administration
    • Only five email-account licenses are included with compatible NAS hardware
    • License packs add cost, and pricing is not published on the official page

  • Mail-in-a-Box — where it wins

    • Bundles Roundcube webmail with IMAP and SMTP access.
    • Automates TLS provisioning, mail DNS setup and system health checks.
    • Control panel manages users, aliases, DNS and backups.

    Where it doesn't

    • Requires a dedicated machine and ongoing server administration.
    • Community is the listed support channel.
    • Listed integration is limited to Amazon S3.
  • Synology MailPlus Server8.6/10 · Free plan

    A full-featured mail server for organizations already running compatible Synology NAS hardware.

    Visit SynologyFull verdict →
  • Mail-in-a-Box8.4/10 · Free plan

    A free, open-source mail server bundle for small teams ready to administer their own infrastructure.

    Visit Mail-in-a-BoxFull verdict →

More comparisons

All email server software comparisons → · Full ranking →

Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026

Last updated · How we research and update