Device previews
Before send
Run render previews to catch layout issues in major mailbox clients.
Preview emails across major clients before you send
MailSlurp helps teams run device previews and compatibility checks to catch layout issues, broken links, and missing images before campaigns and releases go live.
Compatibility
Feature intelligence
Detect unsupported HTML/CSS patterns and reduce client-specific surprises.
Content checks
Links and images
Catch broken links and missing images that reduce conversion and trust.
Repeatable runs
Trend tracking
Compare before/after runs when templates change to prevent regressions.
Core capabilities
What teams need when email workflows matter
Render previews across devices and mailbox clients
Compare how your email appears across providers and devices so layout issues are caught before customers see them.
- Gmail
- Outlook
- Yahoo
Compatibility checks for HTML and CSS features
Detect email features and identify compatibility risks for clients and operating systems you care about.
- HTML
- CSS
- Client support
Broken link and missing image detection
Protect conversion-critical CTAs by detecting 404 links, invalid redirects, and missing assets.
- Links
- Images
- Quality gates
Use trend history as a release and campaign KPI
Track render outcomes over time and compare before/after template changes to prevent regressions.
- Trends
- Baselines
- Run history
Team use cases
How engineering, QA, and operations teams use MailSlurp
Marketing ops
Pre-send rendering QA for campaigns
Catch layout issues and broken CTAs before a campaign reaches customers.
- Reduce conversion loss from layout regressions
- Prevent broken links and missing images
- Standardize pre-send QA across teams
Release teams
Compatibility checks as release gates
Treat email templates like production code and block risky changes with repeatable render checks.
- Detect client-specific failures early
- Compare before/after template refactors
- Keep a history of pass/fail evidence
Design and content teams
Confidence in responsive layouts
Validate responsive behavior across devices so emails look consistent and trustworthy.
- Preview across devices and viewports
- Reduce last-minute launch surprises
- Ship consistent brand experience
Getting started
Get this working quickly, then build on it
Day 1
Run one render preview for a critical template
Start with one template and confirm that previews and checks surface meaningful issues.
- Pick a critical template (activation, billing, lifecycle)
- Run device previews and a compatibility check
- Record baseline outcomes and known risks
Week 1
Add quality gates for links and images
Make sure conversion-critical CTAs do not ship broken.
- Fail checks when critical links are invalid
- Detect missing assets and content defects
- Route defects to owners with clear remediation tasks
Week 2+
Operationalize with trend reporting
Use run history to prevent regressions across campaigns and releases.
- Compare before/after runs after template changes
- Define threshold rules for key clients
- Pair with deliverability tests for receipt confidence
Team fit
How different teams get value
Marketing ops
Challenge: Rendering issues and broken links often show up after send when impact is highest.
What improves: Run previews and checks before launch and keep quality consistent.
Release teams
Challenge: Template changes can regress in specific clients and devices without warning.
What improves: Treat rendering checks as release gates with clear pass/fail evidence.
Design teams
Challenge: Responsive layouts are hard to validate across mailbox clients consistently.
What improves: Preview across clients and devices with repeatable runs.
Customer outcomes
What gets better once MailSlurp is in place
Fewer broken emails
Catch rendering issues and content defects before customers see them.
Better conversion protection
Protect CTAs by validating links, images, and layout consistency.
Repeatable release evidence
Keep run history and trend reporting for stakeholders and audits.
Works with QA workflows
Pair rendering checks with deliverability and campaign audits for end-to-end confidence.
Ready to try this with your own workflow?
FAQ
Questions people ask before they start
Is this only for marketers?
No. Engineering and QA teams use rendering checks as release gates, while marketing ops teams use them for pre-send QA.
Do you also check deliverability and inbox placement?
Yes. Pair rendering checks with deliverability tests to validate inbox receipt and sender posture before launch.
What should we check first?
Start with rendering previews and broken link checks on your most conversion-critical templates.
Can we track quality over time?
Yes. Use run history and trend views to compare before and after template changes.