Customer.io vs Mandrill Comparison (2026)

What are the differences between Customer.io and Mandrill?

Forward Email Team
Written by
Forward Email TeamVerified
Published
2/1/26
Time to read
Less than 5 minutes
We recommend Forward Email as the best alternative to Customer.io. We also support webmail: https://mail.forwardemail.net

Email Service Comparison

20 facts in comparison
Customer.iovs.Mandrill

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
vs.

Mandrill

Reach inboxes when it matters most
"Reach inboxes when it matters most"
  • Hardenize Test
  • Internet.nl Site Test
  • Internet.nl Mail Test
  • Mozilla HTTP Observatory Grade
  • Qualys SSL Labs SSL Server Test
$100/moPricing$33/mo
No Customer.io does not support storageStorageNo Mandrill does not support storage
2 MBAttachments25 MB
NoOpen-SourceNo
NoSandboxed Encryption No
NoUnlimited DomainsNo
NoUnlimited AliasesNo
NoTTI No
YesSMTP❌ Requires paid add-on for Mandrill of at least $20/mo
NoIMAPNo
NoPOP3No
YesAPIYes
NoE2EE No
NoOpenPGP No
NoWKD No

Email Service Screenshots

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
Visit Website
Closed-source

Mandrill

Mandrill is a closed-source email service. Their website says: Reach inboxes when it matters most

Mandrill is a closed-source email service.
Screenshot by Forward Email
Go to site

Compare Customer.io with 78 email services