Abnormal Security vs Proton Mail Comparison (2026)

What are the differences between Abnormal Security and Proton Mail?

Written by

Forward Email Team

Published

2/1/26

Time to read

Less than 5 minutes

We recommend Forward Email as the best alternative to Abnormal Security. We also support webmail: https://mail.forwardemail.net

Email Service Comparison

20 facts in comparison

Abnormal Security	vs.	Proton Mail
Abnormal Security "Cloud Email Security - Block Malicious Email Attacks" Website	vs.	Proton Mail "Secure email that protects your privacy" Website
Requires you to talk to a sales team	Pricing	$3.99/mo
Requires 3rd party	Storage	15 GB
Unknown	Attachments	25 MB
No	Open-Source	❌ Proton Mail claims to be open-source, but their back-end actually is closed source
No	Sandboxed Encryption	No
No	Unlimited Domains	No
No	Unlimited Aliases	No
No	TTI	No
❌ Requires 3rd party	SMTP	❌ Requires you to download Proton Mail Bridge and forces vendor lock-in
❌ Requires 3rd party	IMAP	❌ Requires you to download Proton Mail Bridge and forces vendor lock-in
❌ Requires 3rd party	POP3	❌ Proton Mail does not support POP3
Yes	API	No
No	E2EE	⚠️ Proton Mail rewrites your emails
No	OpenPGP	Yes
No	WKD	Yes