How do I keep sensitive data out of MailBlastr?

MailBlastr keeps a per-email log so you can see delivery status, debug failures, and correlate webhook events. That means the content you put into an email is retained for a time as part of that record. Treat anything you send as data MailBlastr stores, and keep secrets you do not want logged out of it.

What is retained

For each email you send, the log typically retains:

• The envelope: from, to, cc/bcc, and reply-to addresses.
• The subject line.
• The message body (HTML and/or text) and any custom headers you set.
• Delivery events: sent, delivered, bounce, complaint, open, and click.

How to avoid storing secrets

• Do not put raw secrets in the subject or body. Passwords, full API keys, card numbers, and similar values should never be the literal content of an email.
• Send a link, not the secret. For password resets, magic links, or one-time access, send a short-lived, single-use URL that resolves to the sensitive value on your own system instead of embedding the value itself.
• Minimize personal data. Only include the recipient details the message genuinely needs.
• Keep internal identifiers out of the subject. Subjects are the most visible part of the log; put correlation IDs in custom headers or your own metadata rather than the subject line.

Turning off message-content storage

For accounts with stricter compliance needs, MailBlastr can turn off storage of message content — subjects and bodies are not retained in the log, while delivery metadata and events still are. This is offered to established, good-standing senders rather than brand-new accounts, since it relies on a healthy sending history.

If your account has a steady sending history and a low bounce rate and you need content storage disabled, contact support to have it enabled.