N‑able Mail Assure vs Proton Mail Comparison (2025)

What are the differences between N‑able Mail Assure and Proton Mail?

Written by

Forward Email Team

Published

7/1/25

Time to read

Less than 5 minutes

We recommend Forward Email as the best alternative to N‑able Mail Assure.

Email Service Comparison

20 facts in comparison

N‑able Mail Assure	vs.	Proton Mail
N‑able Mail Assure "Email protection to help you secure and scale" 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
Depends on inbound/outbound (e.g. 10 MB)	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

Email Service Screenshots

Closed-source

N‑able Mail Assure

N‑able Mail Assure is a closed-source email service. According to their website: Email protection to help you secure and scale

N‑able Mail Assure is a closed-source email service.

Screenshot by Forward Email

Closed-source

Proton Mail

Proton Mail is a closed-source email service. Their official description reads: Secure email that protects your privacy

Proton Mail is a closed-source email service.

Photograph by Forward Email

Compare N‑able Mail Assure with 78 email services