DuoCircle vs Fastmail Comparison (2026)

What are the differences between DuoCircle and Fastmail?

Forward Email Team
Written by
Forward Email TeamVerified
Published
2/1/26
Time to read
Less than 5 minutes
We recommend Forward Email as the best alternative to DuoCircle. We also support webmail: https://mail.forwardemail.net

Email Service Comparison

20 facts in comparison
DuoCirclevs.Fastmail

DuoCircle

Protect Email Against Phishing, Spam and Malware
"Protect Email Against Phishing, Spam and Malware"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
vs.

Fastmail

Fast, private email that’s just for you
"Fast, private email that’s just for you"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
Requires you to talk to a sales teamPricing$3/mo
Requires 3rd partyStorage2 GB
50 MBAttachments70 MB
NoOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
NoTTI No
❌ Requires 3rd partySMTPYes
❌ Requires 3rd partyIMAPYes
❌ Requires 3rd partyPOP3Yes
YesAPINo
NoE2EE No
NoOpenPGP ⚠️ Fastmail does support PGP, but not in their webmail; see this blog post for insight
NoWKD No

Email Service Screenshots

Closed-source

DuoCircle

DuoCircle is a closed-source email service. According to their website: Protect Email Against Phishing, Spam and Malware

DuoCircle is a closed-source email service.
Photograph by Forward Email
Visit Website
Closed-source

Fastmail

Fastmail is a closed-source email service. Their official description reads: Fast, private email that’s just for you

Fastmail is a closed-source email service.
Screenshot by Forward Email
Go to site

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