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Average Ratings 0 Ratings

Total
ease
features
design
support

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Write a Review

Description

Coldletter is an email design and automation layer that helps teams create, manage, and send product emails without replacing their existing email provider. It connects with delivery services such as SendGrid, Postmark, Amazon SES, Mailgun, Resend, and SparkPost, giving companies flexibility while keeping sending infrastructure intact. The platform includes a visual editor where teams can build templates, add variables, reuse blocks, and preview emails across clients such as Gmail, Outlook, and Apple Mail. Every template is designed to be responsive, accessible, and safe for dark mode by default. Developers can trigger templates through a single API request while Coldletter handles rendering, data merging, routing, retries, suppression, and idempotency. Marketing, lifecycle, design, and product teams can use the platform to manage email content without constantly relying on engineering for every change. Journey automation tools allow users to create workflows based on events, schedules, engagement, attributes, or A/B testing paths. Version control, template diffs, rollbacks, localization, test sends, roles, approvals, and analytics help teams manage production emails with more confidence. Coldletter gives organizations a structured way to build polished product emails while improving collaboration between technical and non-technical teams.

Description

Email Creation Platform. Email creation can be dramatically reduced without the need for additional staff or compromises in quality. Stensul integrates seamlessly with the most popular automation platforms. You can optimize your team's resources without having to hire staff or compromise on quality. Guardrails allow marketers to create emails in minutes. Facilitate collaboration so teams can create high-performing emails that deliver results. Instead of communicating in disconnected messaging platforms, an end-to-end platform connects all team members.

API Access

Has API No 

API Access

Has API No 

Screenshots View All

No images available

Screenshots View All

Integrations

Acoustic Campaign No 
Adobe Campaign No 
Adobe Marketo Engage No 
Amazon SES Yes 
Braze No 
Eloqua No 
HubSpot CRM No 
HubSpot Customer Platform No 
HubSpot Marketing Hub No 
Iterable No 
Marigold Engage No 
Marigold Engage+ No 
Marigold LiveContent by Liveclicker No 
Microsoft Outlook No 
Movable Ink No 
Oracle Responsys No 
Postmark Yes 
Salesforce Agentforce Marketing No 
Salesforce Marketing Cloud Account Engagement No 
SendGrid Yes 

Integrations

Acoustic Campaign Yes 
Adobe Campaign Yes 
Adobe Marketo Engage Yes 
Amazon SES No 
Braze Yes 
Eloqua Yes 
HubSpot CRM Yes 
HubSpot Customer Platform Yes 
HubSpot Marketing Hub Yes 
Iterable Yes 
Marigold Engage Yes 
Marigold Engage+ Yes 
Marigold LiveContent by Liveclicker Yes 
Microsoft Outlook Yes 
Movable Ink Yes 
Oracle Responsys Yes 
Postmark No 
Salesforce Agentforce Marketing Yes 
Salesforce Marketing Cloud Account Engagement Yes 
SendGrid No 

Pricing Details

$0
Free Trial No 
Free Version Yes 

Pricing Details

No price information available.
Free Trial No 
Free Version No 

Deployment

Web-Based Yes 
On-Premises No 
iPhone App No 
iPad App No 
Android App No 
Windows No 
Mac No 
Linux No 
Chromebook No 

Deployment

Web-Based No 
On-Premises No 
iPhone App No 
iPad App No 
Android App No 
Windows No 
Mac No 
Linux No 
Chromebook No 

Customer Support

Business Hours No 
Live Rep (24/7) No 
Online Support Yes 

Customer Support

Business Hours Yes 
Live Rep (24/7) No 
Online Support Yes 

Types of Training

Training Docs Yes 
Webinars No 
Live Training (Online) No 
In Person No 

Types of Training

Training Docs No 
Webinars No 
Live Training (Online) No 
In Person No 

Vendor Details

Company Name

Optosoftware inc.

Founded

2025

Country

Canada

Website

coldletter.com

Vendor Details

Company Name

stensul

Country

United States

Website

stensul.com

Product Features

Email Marketing

A/B Testing No 
Artificial Intelligence No 
Auto-Responders No 
CAN SPAM Compliance No 
Customer Surveys No 
Drip Campaigns No 
Dynamic Content No 
Event Triggered Email No 
Image Library No 
Landing Pages/Web Forms No 
Mailing List Management No 
Mobile Optimized Emails No 
Reporting/Analytics No 
Subscriber Management No 
Template Management No 
WYSIWYG Email Editor No 

Email Template Design

A/B Testing No 
Code From Scratch No 
Drag & Drop Editing No 
Image Library No 
Import HTML Code No 
Mobile-Friendly / Responsive No 
Potential Issue Identification No 
Premade Templates No 
Proofing No 
Reporting / Analytics No 
Text Editor No 
Theme Editor No 

Product Features

Email Marketing

A/B Testing Yes 
Artificial Intelligence No 
Auto-Responders No 
CAN SPAM Compliance Yes 
Customer Surveys No 
Drip Campaigns No 
Dynamic Content Yes 
Event Triggered Email No 
Image Library Yes 
Landing Pages/Web Forms No 
Mailing List Management No 
Mobile Optimized Emails Yes 
Reporting/Analytics No 
Subscriber Management No 
Template Management Yes 
WYSIWYG Email Editor No 

Email Template Design

A/B Testing No 
Code From Scratch No 
Drag & Drop Editing No 
Image Library No 
Import HTML Code No 
Mobile-Friendly / Responsive No 
Potential Issue Identification No 
Premade Templates No 
Proofing No 
Reporting / Analytics No 
Text Editor No 
Theme Editor No 

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