DuoCircle vs Fastmail Comparison (2025)

What are the differences between DuoCircle and Fastmail?

Forward Email Team
Written by
Forward Email TeamVerified
Published
7/1/25
Time to read
Less than 5 minutes
We recommend Forward Email as the best alternative to DuoCircle.

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

Compare DuoCircle with 78 email services