Proton Mail vs Altospam Comparison (2026)

Compare Proton Mail vs Altospam email services. In-depth analysis of features, pricing, security, privacy, and storage to find the best email provider for your needs.

Written by

Forward Email Team

Published

4/1/26

Time to read

Less than 5 minutes

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

Email Service Comparison

20 facts in comparison

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