1. Direct support channels & operational SLAs
MailCheckup provides direct human technical assistance operated by deliverability specialists. We do not use offshore ticket deflection or automated bots:
| Department / Subject | Email Address | Guaranteed Response SLA | Primary Resolution Purpose |
|---|---|---|---|
| Technical Support & Deliverability | support@mailcheckup.net | < 4 business hours | Diagnostic review of list results, catch-all routing, and bounce prevention. |
| Billing & Invoicing | billing@mailcheckup.net | < 2 business hours | Stripe checkout questions, PDF invoice downloads, and 7-day refunds. |
| API & Developer Engineering | support@mailcheckup.net | < 4 business hours | Bearer authentication, webhook HMAC setup, and MCP agent connection. |
| Wholesale & Agency Procurements | support@mailcheckup.net | < 2 business hours | Custom high-volume credit packs exceeding 1,000,000 checks. |
| Security & Responsible Disclosure | security@mailcheckup.net | < 24 hours | Vulnerability disclosures, safe harbor reports, and compliance audits. |
2. Invoicing, Stripe, & Secuno LLC billing
Paid purchases are processed securely through Stripe Checkout. Upon completion, credits appear immediately in your workspace ledger. An official MailCheckUP invoice numbered MCU-YYYYMMDD-#### is automatically generated by Secuno LLC and available for PDF download in the portal. Unused credits qualify for our voluntary 7-day refund window upon email request to billing@mailcheckup.net.
3. Corporate identity & postal address
MailCheckup is operated by Secuno LLC. Corporate inquiries and legal correspondence should be directed to:
- Legal Entity: Secuno LLC
- Physical Headquarters: 30 N Gould St, Sheridan, WY 82801, USA
- Corporate Phone: +1 (315) 961-7074
- Portal Dashboard: cp.mailcheckup.net
4. Frequently asked support questions
What is the official response time for support inquiries?
Technical and product inquiries sent to support@mailcheckup.net receive responses from deliverability specialists within 4 business hours. Billing and invoice inquiries sent to billing@mailcheckup.net are addressed within 2 business hours.
Where can I download official PDF invoices for my purchases?
Official MailCheckUP invoices (numbered MCU-YYYYMMDD-####, issued by Secuno LLC) are available for immediate PDF download in the Billing section of the customer portal at cp.mailcheckup.net immediately after Stripe confirms authorization.
Does MailCheckup provide phone support for urgent issues?
Yes. Our corporate headquarters telephone line is +1 (315) 961-7074 during standard US business hours (9am–5pm Mountain Time / Wyoming). For fastest technical review, email support@mailcheckup.net with your Job ID so our engineering team can inspect server logs.
How do I submit a voluntary refund request within 7 days?
Send an email to billing@mailcheckup.net within 7 calendar days of your transaction date with your account email and Stripe charge reference. Unused purchased credits are refunded directly back to your original payment card via Stripe.
Can we request a custom Data Processing Addendum (DPA)?
Yes. Enterprise workspaces and agencies processing European customer data can review our standard GDPR Article 28 DPA at /data-processing-addendum/ or request an executed PDF copy by emailing legal@mailcheckup.net or support@mailcheckup.net.
How do I report a security vulnerability responsibly?
Submit security concerns to security@mailcheckup.net with minimal reproduction steps. Do not attempt to access, extract, or destroy other customers' data. MailCheckup operates under safe harbor for responsible ethical researchers.