DuoCircle vs Postmark Comparison (2025)

What are the differences between DuoCircle and Postmark?

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.Postmark

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.

Postmark

The email delivery service that people actually like
"The email delivery service that people actually like"
  • 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$15/mo
Requires 3rd partyStorageNo Postmark does not support storage
50 MBAttachments10 MB
NoOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
NoTTI TTI
❌ Requires 3rd partySMTPYes
❌ Requires 3rd partyIMAPNo
❌ Requires 3rd partyPOP3No
YesAPIYes
NoE2EE No
NoOpenPGP No
NoWKD No

Email Service Screenshots

Closed-source

DuoCircle

DuoCircle is a closed-source email service. Their website says: Protect Email Against Phishing, Spam and Malware

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

Postmark

Postmark is a closed-source email service. Its description from its website is: The email delivery service that people actually like

Postmark is a closed-source email service.
Photograph by Forward Email
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Compare DuoCircle with 78 email services