Postmark vs Mimecast Comparison (2025)

What are the differences between Postmark and Mimecast?

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 Postmark.

Email Service Comparison

20 facts in comparison
Postmarkvs.Mimecast

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
vs.

Mimecast

Email & Collaboration Security
"Email & Collaboration Security"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
$15/moPricingSee Mimecast plans (requires you to talk to a sales team) (according to a Reddit thread it may cost upwards of +$1000-2000 per month)
No Postmark does not support storageStorageUnknown
10 MBAttachments200 MB
NoOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
TTI TTI 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

Postmark

Postmark is a closed-source email service. Their official description reads: The email delivery service that people actually like

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

Mimecast

Mimecast is a closed-source email service. Their official description reads: Email & Collaboration Security

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