What’s “silent rejection” behavior in Apple Mail?

Apple Mail's silent rejection behavior refers to situations where iCloud accepts messages at the SMTP level but subsequently discards them without notification. Unlike bounce messages that inform senders of delivery failures, silently rejected messages simply disappear.

This behavior makes detecting delivery problems at iCloud challenging. Your sending logs show successful delivery, but messages never reach recipients. Without feedback loops or detailed postmaster tools from Apple, senders may remain unaware of issues.

Identifying silent rejections requires testing with seed accounts at iCloud addresses and comparing delivered counts against expected delivery. If iCloud seeds consistently miss messages that reach other providers, silent filtering is likely occurring. Resolution requires investigating authentication, content, and reputation factors, though Apple provides limited diagnostic information.