Side by side

Inbox Warmup vs Mailwarmup

Both stand on email warmup software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.

Inbox Warmup

Free trial APIWeb

Inbox Warmup combines SMTP setup checks, gradual warm-up, mailbox monitoring, and campaign controls. Consider the account-wide hourly limits and non-rolling credits when choosing a plan.

Visit Inbox Warmup

Mailwarmup combines scheduled warmup interactions with deliverability monitoring and sending controls. Its trial gives you a way to assess the service, but warmup alone cannot guarantee inbox placement.

Visit Mailwarmup

The facts

	Inbox Warmup	Mailwarmup
Free plan	A free trial	A free trial
Open source	Not published	Not published
Runs on	API, Web	Web
Lowest paid plan	Launch: $39 a month	Starter: $19 a month
Plans published	4	4
Maker	Not published	Not published
Website	inboxwarmup.io	mailwarmup.app
On email warmup software	#15 of 24	#19 of 24

Inbox Warmup: what it does well

Supports SSL/TLS, STARTTLS, and compatible custom SMTP ports
Checks SPF, DKIM, DMARC, and other domain records
Warm-up can pause when health signals need attention
Includes campaign scheduling and sending limits
Offers free SPF and DMARC checkers and an SMTP tester

What to know first

No free plan
Launch limits sending to 75 emails/hour account-wide
Monthly credits do not roll over
Warm-up does not guarantee inbox placement, opens, or replies

Mailwarmup: what it does well

Shared network includes more than 10,000 inboxes.
Supports Gmail, Outlook, and SMTP integrations.
Schedule daily interactions and control sending limits.
Dashboard tracks deliverability and messages removed from spam.
7-day trial is available.

What to know first

No free plan.
Requires SMTP and IMAP account details.
Warmup does not guarantee messages avoid spam.
AI ramp ups are in beta.

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