MailSlurp logo

A MailReach alternative for sender warmup and campaign checks.

Warm your sender gradually, check inbox placement and review the actual campaign before launch. MailSlurp keeps those checks together.

Illustration of a campaign arriving in the inbox with Gmail, Outlook and Yahoo

Trusted by teams at

  • Broadcom
  • Scraper
  • Trivago
  • Avast
  • Wolt
  • Panasonic
  • Broadcom
  • Scraper
  • Trivago
  • Avast
  • Wolt
  • Panasonic

Reach customers across every major inbox.

Build sending history gradually and check placement across available Gmail, Outlook, Yahoo, and other provider samples as your schedule progresses.

Track inbox, Promotions, spam, and not-received results throughout the ramp to make informed decisions before increasing campaign volume.

Improve inbox placement
A campaign email reaching customer inboxes
Yahoo, Gmail, Outlook, Proton Mail, and iCloud provider cards

Reach personal inboxes

Improve reach across the personal inboxes customers use every day, with placement results for each provider.

Microsoft 365 and Google Workspace provider cards

Reach business inboxes

Check available Microsoft 365 and Google Workspace samples before increasing business email volume.

Spam score improving over repeated delivery checks

Move further from spam

Compare inbox and spam results over time to see whether your sender is ready for more volume.

Build the reputation behind every campaign.

New and recovering senders need a record of consistent, successful delivery. MailSlurp creates that history before launches, promotions, lifecycle messages, and customer notifications depend on it.

Volume grows in measured steps while receipt, placement, and sender-health observations stay visible.

Build sender reputation
Campaign email moving from Promotions to the Primary inbox on iPhone
Sending volume increasing in safe measured steps

Grow without sudden spikes

Increase sending volume in steady steps that build trust instead of triggering the reputation damage caused by abrupt spikes.

SPF, DKIM, DMARC, and blocklist health checks

Keep the sender healthy

Keep authentication, domain health, and blocklist signals in view while the sender builds a stronger delivery record.

Sender recovery trend rising back toward the inbox

Recover lost trust

Use a measured recovery schedule to observe an existing sender and decide when to increase volume.

Protect deliverability while volume grows.

MailSlurp uses controlled inbox receipts, delivery failures, domain health, Gmail Postmaster data, and placement tests to choose the next target. Strong signals keep the ramp moving; weaker signals slow it before customer reach drops.

Use each step to assess delivery before increasing volume. Placement also depends on your authentication, content, and recipient engagement.

Start adaptive warmup
Adaptive sending volume increasing, holding, and resuming
Email placement across inbox, Promotions, and spam

Know exactly where mail lands

Measure inbox, Promotions, spam, and not-received outcomes instead of treating provider acceptance as the finish line.

Inbox placement history revealing a delivery change

Catch placement changes early

See when inbox reach changes during the ramp and adjust before important customer campaigns are affected.

Slack and Microsoft Teams delivery notifications

Keep the team ahead

Bring placement changes into Slack or Microsoft Teams so the people protecting deliverability can act quickly.

Warm up every sender you already use.

Connect your provider through a supported native integration or authenticated SMTP, then warm up the mailbox, domain, and identity used for your customer email.

Use SendGrid, Resend, Amazon SES, Mailgun, Postmark, Gmail, Microsoft 365, Yahoo, Zoho, Fastmail, Brevo, Mailjet, and more.

Connect your provider
SendGrid, Resend, Amazon SES, and Mailgun provider cards

How to start warming your sender

Connect and verify the sender

Choose a supported provider or authenticated SMTP connection. Verify the From address and complete the test delivery. The provider guides explain the connection details.

Choose a gradual schedule

Set a new-sender or recovery goal, daily target, time zone and sending window. Include your regular campaigns in the total volume and avoid overlapping warmup programs.

Follow results before increasing volume

Check accepted sends, observed receipts and completed provider placement results. Investigate repeated failures before adding volume, then test the finished campaign through its normal ESP. Read the warmup results guide.

Warm the sender. Test the campaign you will send.

Plan around your real sending path

A warmup message and a designed campaign answer different questions. Use MailSlurp to build sending history through a supported connection, then test your newsletter or sales email through the provider that will deliver it.

Carry over recent volume and sending hours

When switching from MailReach, start with the same From address, recent daily volume and sending hours. Check the provider connection, choose a suitable schedule and include normal campaign traffic when setting the target. Compare completed provider checkpoints before increasing volume.

Questions before you switch?

How should I compare a MailReach spam test with MailSlurp?

Use the same sending service, From address and campaign content. Compare the personal and business providers included in each test and inspect individual folder results, keeping Promotions separate from spam. Run your campaign through MailSlurp's placement test even if a separate warmup schedule is already active; the finished message needs its own check. Test a campaign's inbox and spam placement.

What should I carry over when switching from MailReach?

Use the same From address, sending provider, recent daily volume and sending hours when planning the MailSlurp schedule. Verify the connection and avoid running overlapping warmup schedules. Review completed provider checkpoints as volume changes, then test the finished campaign separately through its normal ESP. Understand warmup and placement results.

Can I keep my sending provider?

Yes. Connect a supported sender directly or through authenticated SMTP, verify the From address and complete the test delivery. Use your normal ESP separately for a representative campaign placement test.

Which plans include warmup?

MailSlurp warmup is available on Pro and Growth. Sending usage is billed beyond included credits. Compare the current sender capacity, credits and placement coverage before choosing a plan.

Build sending history. Check the next campaign.

Choose your sender capacity, placement coverage and campaign checks.

Email previews across mobile and desktop clients