SMTP.com vs DuoCircle Comparison (2026)

What are the differences between SMTP.com and DuoCircle?

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 SMTP.com. We also support webmail: https://mail.forwardemail.net

Email Service Comparison

20 facts in comparison
SMTP.comvs.DuoCircle

SMTP.com

Transactional and email relay API
"Transactional and email relay API"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
vs.

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
$25/moPricingRequires you to talk to a sales team
No SMTP.com does not support storageStorageRequires 3rd party
15 MBAttachments50 MB
NoOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
NoTTI No
YesSMTP❌ Requires 3rd party
NoIMAP❌ Requires 3rd party
NoPOP3❌ Requires 3rd party
YesAPIYes
NoE2EE No
NoOpenPGP No
NoWKD No

Email Service Screenshots

Closed-source

SMTP.com

SMTP.com is a closed-source email service. According to their website: Transactional and email relay API

SMTP.com is a closed-source email service.
Photograph by Forward Email
Go to site
Closed-source

DuoCircle

DuoCircle is a closed-source email service. Its description from its website is: Protect Email Against Phishing, Spam and Malware

DuoCircle is a closed-source email service.
Photo by Forward Email
Go to site

Compare SMTP.com with 78 email services