saasrankedSoftware, ranked on the facts

Communication

Best email clients

Read, write and sort mail from all your accounts in one desktop app, with a calendar and the privacy controls you want. 10 email clients, ranked by points out of 100.

Facts checked 8 Oct 2026 · How we score email clients

Not scored yet: The Bat!, Superhuman.

In short

  1. 1
    Mozilla ThunderbirdPeople who want a free, open-source client with built-in encryption
    88/100
    $0cost of a year
  2. 2
    BetterbirdThunderbird users who want more control over how mail is listed, sorted and searched
    78/100
    $0cost of a year
  3. 3
    BlueMailPeople who want a free app with PGP, a calendar and many accounts
    78/100
    $0cost of a year
  4. 4
    eM ClientPeople who want PGP, S/MIME and a calendar in one paid Windows app
    73/100
    $55.87/yrcost of a year
  5. 5
    Microsoft OutlookPeople who want a free app with a calendar, scheduled send and undo send
    67/100
    $0cost of a year
  6. 6
    MailspringPeople with many IMAP, Gmail or Microsoft accounts who want a free, open-source app
    65/100
    $0cost of a year
  7. 7
    Canary MailPeople who want PGP and tracker blocking in an app that also runs on phones
    62/100
    $0cost of a year
  8. 8
    Claws MailPeople who want a small, keyboard-friendly client with strong filtering and PGP
    61/100
    $0cost of a year
  9. 9
    Spark MailPeople with many accounts who use a phone, a Mac and a PC
    56/100
    $0cost of a year
  10. 10
    MailbirdPeople who want a unified inbox and a calendar for several accounts
    52/100
    $77.18/yrcost of a year

How the points add up

Points earned out of the points available in each part of the method.

ProductMail and accounts
of 27		Calendar and contacts
of 9		Privacy and encryption
of 28		Systems and upkeep
of 15		Price
of 21		Total
Mozilla Thunderbird23924112188
Betterbird1592492178
BlueMail22916131878
eM Client23917111373
Microsoft Outlook20610131867
Mailspring2131192165
Canary Mail16611111862
Claws Mail1401972161
Spark Mail2160111856
Mailbird216571352

Each email client in brief

1. Mozilla Thunderbird

Thunderbird suits people who want a free client with a unified inbox, calendar and built-in OpenPGP and S/MIME. Mail stays on your device, per its privacy policy. The catch: Exchange access covers email only, and the vendor pages do not list snooze or undo send.

Best for: People who want a free, open-source client with built-in encryption. Prices, facts and sources

2. Betterbird

Betterbird suits people who like Thunderbird and want extra list, search and layout options without paying anything. It is open source and says it collects no telemetry. The catch: its own pages say little about account types, Gmail or Microsoft sign-in, and Exchange, which are inherited from Thunderbird, and it has no phone app.

Best for: Thunderbird users who want more control over how mail is listed, sorted and searched. Prices, facts and sources

3. BlueMail

BlueMail suits people who want a free app on every system, with a unified inbox, calendar, PGP and CalDAV. It says mail is not stored on its servers and tracking pixels are blocked by default. The catch: S/MIME is limited to Enterprise licences, and the pages show no scheduled send or rules.

Best for: People who want a free app with PGP, a calendar and many accounts. Prices, facts and sources

4. eM Client

eM Client suits people who want PGP, S/MIME, CalDAV and a built-in calendar in one app, and who are happy to pay €49.95 a year for unlimited accounts. The catch: the free plan stops at 2 accounts, and the vendor's pages do not describe a unified inbox.

Best for: People who want PGP, S/MIME and a calendar in one paid Windows app. Prices, facts and sources

5. Microsoft Outlook

Outlook suits people who want a free Windows mail app with a built-in calendar and mail tools such as schedule send, snooze and undo send. Classic Outlook blocks picture downloads by default. The catch: the free version shows ads, and Microsoft's pages do not describe a unified inbox or OpenPGP.

Best for: People who want a free app with a calendar, scheduled send and undo send. Prices, facts and sources

6. Mailspring

Mailspring suits people who want to read many IMAP, Gmail and Microsoft accounts in one free, open-source app. Pro adds unlimited snooze and send later for $85 a year. The catch: it has no POP3 or Exchange support, no mobile apps listed, and its full calendar is announced for later this year.

Best for: People with many IMAP, Gmail or Microsoft accounts who want a free, open-source app. Prices, facts and sources

7. Canary Mail

Canary Mail suits people who want a free client for many accounts, or who want PGP and tracker blocking across desktop and phone. Growth at $36 a year adds Send Later and a calendar. The catch: monthly billing is not offered, and the privacy policy describes some server-side handling for push notifications and AI features.

Best for: People who want PGP and tracker blocking in an app that also runs on phones. Prices, facts and sources

8. Claws Mail

Claws Mail suits people who want a free, light client with filters, templates, GnuPG and S/MIME. The catch: Gmail and Microsoft sign-in needs you to register your own app first, Exchange works only through IMAP, and the pages show no unified inbox or delayed send, with a calendar only through a plugin.

Best for: People who want a small, keyboard-friendly client with strong filtering and PGP. Prices, facts and sources

9. Spark Mail

Spark suits people who want one free app on every device, with unlimited accounts, a unified inbox and a calendar. Plus adds templates and AI. The catch: Spark states that some features need server-side processing of mail, and no OpenPGP, S/MIME or rules are listed.

Best for: People with many accounts who use a phone, a Mac and a PC. Prices, facts and sources

10. Mailbird

Mailbird suits people who run several mail accounts on Windows and want a unified inbox, calendar and snooze in one app. Mail stays on your computer, per the vendor. The catch: the free plan allows one account, and PGP, S/MIME and CalDAV are not listed on its pages.

Best for: People who want a unified inbox and a calendar for several accounts. Prices, facts and sources

Every fact, side by side

Each row is one rule of the method and the points it is worth. "–" means the vendor does not publish it, which earns nothing.

Rule (points)Mozilla ThunderbirdBetterbirdBlueMaileM ClientMicrosoft OutlookMailspringCanary MailClaws MailSpark MailMailbird
Account types (12)4 of 42 of 44 of 44 of 43 of 42 of 42 of 43 of 43 of 42 of 4
Unified inbox (4)YesYesYes––YesYes–YesYes
Mail tools (8)2 of 41 of 43 of 44 of 44 of 44 of 43 of 41 of 44 of 44 of 4
Filters and rules (3)YesYes–YesYesYes–Yes–Yes
Built-in calendar (6)YesYesYesYesYesNoYes–YesYes
CalDAV and CardDAV (3)YesYesYesYes–Yes––––
OpenPGP (7)YesYesYesYes––YesYes––
S/MIME (6)YesYesNoYesYes––Yes––
Blocks tracking pixels (4)––YesYesYes–Yes–––
Open-source apps (6)YesYes–––Yes–Yes––
Mail stays on your device (5)YesYesYes––Yes––NoYes
Other systems (10)3 of 52 of 54 of 53 of 54 of 52 of 53 of 51 of 53 of 51 of 5
Released in the last year (5)YesYesYesYesYesYesYesYesYesYes
No ads in the app (3)YesYes–YesNoYes–Yes–Yes
Free plan (6)YesYesYesYesYesYesYesYesYesYes
Cost of a year (12)$0$0$0$55.87/yr$0$0$0$0$0$77.18/yr

Head to head

We read each vendor's own pages, record every fact with its source and date, and score it by the rules on how we score email clients. A tie goes to the lower price. Email apps for one person or a small team that run on Windows (an app, or in the browser). Mail hosting, encrypted mailbox services and bridges are left out. A feature counts if it is on at least one plan for individuals, in any of the vendor's Windows mail apps (new and classic Outlook count together). Price lines use plans for individuals. Vendor claims about speed or quality are shown on product pages but never scored. Prices are in US dollars before tax.