N‑able Mail Assure vs Posteo Comparison (2025)

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

Forward Email Team
Written by
Forward Email TeamVerified
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 Assurevs.Posteo

N‑able Mail Assure

Email protection to help you secure and scale
"Email protection to help you secure and scale"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
vs.

Posteo

Green, secure, ad-free
"Green, secure, ad-free"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
Requires you to talk to a sales teamPricing€1/mo
Requires 3rd partyStorage2 GB
Depends on inbound/outbound (e.g. 10 MB)Attachments50 MB
NoOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
NoTTI No
❌ Requires 3rd partySMTPYes
❌ Requires 3rd partyIMAPYes
❌ Requires 3rd partyPOP3Yes
YesAPINo
NoE2EE ⚠️ Opt-in
NoOpenPGP Yes
NoWKD Yes

Email Service Screenshots

Closed-source

N‑able Mail Assure

N‑able Mail Assure is a closed-source email service. Its description from its website is: Email protection to help you secure and scale

N‑able Mail Assure is a closed-source email service.
Photograph by Forward Email
Visit Website
Closed-source

Posteo

Posteo is a closed-source email service. Its description from its website is: Green, secure, ad-free

Posteo is a closed-source email service.
Screenshot by Forward Email
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Compare N‑able Mail Assure with 78 email services