Reference
Reply-To removed when it matches From
Emailit now drops the Reply-To header when it contains the same addresses as From, because spam filters penalize the duplicate.
Updated Sep 29, 2026
ChangedEmail APISMTP relayDeliverability
Emailit compares the addresses in Reply-To and From, ignoring display names and letter case. When they’re the same, it removes Reply-To before signing the message. Replies still reach the From address.
When the addresses differ, Reply-To is kept unchanged. See Email headers.