MailSlurp guides

How to Preview Email in Apple Mail on Mac, iPhone and iPad

Catch layout and image problems across Apple devices before you send. Use MailSlurp to compare the same email on Mac, iPhone and iPad.

SVG or PNG for Email Logos? A Real Gmail and Outlook Comparison

Compare linked SVG, inline SVG and PNG in five real email clients. Choose a reliable campaign logo and test its size, visibility and dark-mode treatment.

Why Your Hidden Email Preheader Appears in the Message

Fix preview text leaking above your campaign. See a real Gmail mobile repair, check your ESP settings, and approve the inbox snippet and opened email separately.

Your Email Background Disappeared: Keep the Message Readable

See how one email background changes in Outlook and Gmail, then choose a solid-color fallback or foreground image that preserves the campaign's offer.

Your Email Font Changed: How to Fix Wrapping and Fallbacks

Test what happens when a campaign uses its fallback font. Compare real Gmail, Outlook and Apple Mail results, then repair crowded headings, prices and buttons.

How to Warm Up Email in HubSpot Before Your Next Campaign

Decide whether you are warming a HubSpot sending domain, marketing dedicated IP, or separate mailbox, then test the real campaign before increasing volume.

SMS & OTP

Using Page Object Model (POM) for E2E MFA testing

Build Page Object Model tests for email and SMS verification with Selenium, TestNG, and Playwright. Create inboxes, wait for OTPs, extract codes, and complete authentication.

Amazon SES Warmup: From Sandbox Checks to a Verified Sender

Prepare Amazon SES for email warmup with regional identity checks, production access and SES SMTP credentials, then monitor sending and placement in MailSlurp.

ESMailSlurp guide

Email Subdomains: Setup, Authentication and Warmup

Learn what an email subdomain is, how From, Return-Path and DKIM domains fit together, and how to verify a new sender before warming it up.

GPMailSlurp guide

Google Postmaster Tools: Setup, Missing Data and Sender Checks

Set up Google Postmaster Tools, troubleshoot missing Gmail data, understand the v2 reputation-dashboard changes, and pair the results with MailSlurp sender checks.

How to Measure Email Warmup with Inbox Placement Checks

Read MailSlurp warmup results by provider, compare completed placement checkpoints, and separate accepted sends, inbox observations and sender readiness.

Mailgun Warmup: Connect Your Domain and Check Delivery

Connect a verified Mailgun domain to MailSlurp with a domain sending key, choose the correct region, and compare warmup activity with delivery and placement results.