Klaviyo vs Startmail Comparison (2025)

What are the differences between Klaviyo and Startmail?

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 Klaviyo.

Email Service Comparison

20 facts in comparison
Klaviyovs.Startmail

Klaviyo

Power smarter digital relationships
"Power smarter digital relationships"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
vs.

Startmail

Private email you can trust
"Private email you can trust"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
$20/moPricing$7/mo
No Klaviyo does not support storageStorage20 GB
0 MBAttachments25 MB
NoOpen-SourceNo
NoSandboxed Encryption ❌ Startmail claims to use a User Vault, but this statement has not been audited and their source code is closed-source
NoUnlimited DomainsNo
NoUnlimited AliasesNo
NoTTI No
NoSMTPYes
NoIMAPYes
NoPOP3Yes
NoAPINo
NoE2EE ⚠️ Supported if both sender and recipient are using OpenPGP
NoOpenPGP ⚠️ Supports OpenPGP, but does not support WKD
NoWKD No

Email Service Screenshots

Closed-source

Klaviyo

Klaviyo is a closed-source email service. Its description from its website is: Power smarter digital relationships

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

Startmail

Startmail is a closed-source email service. Their website says: Private email you can trust

Startmail is a closed-source email service.
Screenshot by Forward Email
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Compare Klaviyo with 78 email services