SparkPost email warmup setup

MailSlurp uses credentials owned by your account to send warmup messages. The connection is isolated from MailSlurp's own delivery accounts and can also be reused by automated inbox placement.

Before you connect

1. Verify the sending domain and create an API key with send permission.
2. Confirm that the From address is authorized by the provider.
3. Create a dedicated, least-privilege credential for MailSlurp when the provider allows it.

Connect in MailSlurp

1. Open Email warmup and select Create warmup.
2. Select SparkPost from the sender provider search.
3. Enter a connection name and the authorized From address.
4. Enter the connection values below, then select Verify and continue.
5. Wait for the delivery test to confirm that the provider accepted and delivered the message.
6. Choose a ramp preset, review the schedule, and start the warmup.

Open email warmup in MailSlurp

Connection values

• Use the SMTP host for the account's US or EU region.

Troubleshooting

• Confirm the credential has sending permission and has not expired or been revoked.
• Confirm the From address or domain is verified with the provider.
• For SMTP, confirm the host, port, security mode, and username match the provider settings.
• Check whether an account security policy blocks SMTP or requires an app password.
• Retry the connection test after correcting the provider setting or rotating the credential.

After connection, see email warmup configuration and resultsfor ramp, schedule, content, placement, pause, and resume guidance.