How to Troubleshoot a cPanel Mailbox That Cannot Send Attachments

11/11/2026

Attachment failures may be caused by message size limits, filtering, quota, client behavior, or a receiving server rejection.

Checks to make

Compare a small message with a larger attachment, record the exact bounce, check mailbox and account limits, and inspect mail logs where available. Confirm whether the message left the server before changing limits.

When to get help

Hosting email support can trace message size constraints and delivery logs. Informatix Systems can assess the symptoms, evidence, and next steps. Contact Informatix Systems to discuss this issue.