Proton Mail vs GMX Comparison (2026)

What are the differences between Proton Mail and GMX?

Forward Email Team
Written by
Forward Email TeamVerified
Published
1/1/26
Time to read
Less than 5 minutes
We recommend Forward Email as the best alternative to Proton Mail.

Email Service Comparison

20 facts in comparison
Proton Mailvs.GMX

Proton Mail

Secure email that protects your privacy
"Secure email that protects your privacy"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
vs.

GMX

Create a free email account fast
"Create a free email account fast"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
$3.99/moPricing$29.99/yr
15 GBStorage65 GB
25 MBAttachments100 MB
❌ Proton Mail claims to be open-source, but their back-end actually is closed sourceOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
NoTTI No
❌ Requires you to download Proton Mail Bridge and forces vendor lock-inSMTPYes
❌ Requires you to download Proton Mail Bridge and forces vendor lock-inIMAPYes
❌ Proton Mail does not support POP3POP3Yes
NoAPINo
⚠️ Proton Mail rewrites your emailsE2EE No
YesOpenPGP Yes
YesWKD No

Email Service Screenshots

Closed-source

Proton Mail

Proton Mail is a closed-source email service. According to their website: Secure email that protects your privacy

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

GMX

GMX is a closed-source email service. Their website says: Create a free email account fast

GMX is a closed-source email service.
Photo by Forward Email
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Compare Proton Mail with 78 email services