N‑able Mail Assure vs Startmail Comparison (2025)

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

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.	Startmail
N‑able Mail Assure "Email protection to help you secure and scale" Website	vs.	Startmail "Private email you can trust" Website
Requires you to talk to a sales team	Pricing	$7/mo
Requires 3rd party	Storage	20 GB
Depends on inbound/outbound (e.g. 10 MB)	Attachments	25 MB
No	Open-Source	No
No	Sandboxed Encryption	❌ Startmail claims to use a User Vault, but this statement has not been audited and their source code is closed-source
No	Unlimited Domains	No
No	Unlimited Aliases	No
No	TTI	No
❌ Requires 3rd party	SMTP	Yes
❌ Requires 3rd party	IMAP	Yes
❌ Requires 3rd party	POP3	Yes
Yes	API	No
No	E2EE	⚠️ Supported if both sender and recipient are using OpenPGP
No	OpenPGP	⚠️ Supports OpenPGP, but does not support WKD
No	WKD	No

Email Service Screenshots

Closed-source

N‑able Mail Assure

N‑able Mail Assure is a closed-source email service. Their official description reads: Email protection to help you secure and scale

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

Photograph by Forward Email

Closed-source

Startmail

Startmail is a closed-source email service. Their official description reads: Private email you can trust

Startmail is a closed-source email service.

Photo by Forward Email

Compare N‑able Mail Assure with 78 email services