ImprovMX vs Customer.io Comparison (2025)

What are the differences between ImprovMX and Customer.io?

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 ImprovMX.

Email Service Comparison

20 facts in comparison
ImprovMXvs.Customer.io

ImprovMX

Create free email aliases for your domain name
"Create free email aliases for your domain name"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
vs.

Customer.io

Send messages people actually want to receive using real-time customer data
"Send messages people actually want to receive using real-time customer data"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
$9/moPricing$100/mo
No ImprovMX does not support storageStorageNo Customer.io does not support storage
50 MBAttachments2 MB
NoOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
TTI TTI No
YesSMTPYes
NoIMAPNo
NoPOP3No
YesAPIYes
NoE2EE No
NoOpenPGP No
NoWKD No

Email Service Screenshots

Closed-source

ImprovMX

ImprovMX is a closed-source email service. Their official description reads: Create free email aliases for your domain name

ImprovMX is a closed-source email service.
Photograph by Forward Email
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Closed-source

Customer.io

Customer.io is a closed-source email service. Its description from its website is: Send messages people actually want to receive using real-time customer data

Customer.io is a closed-source email service.
Photograph by Forward Email
Go to site

Compare ImprovMX with 78 email services