kumomta/docs/reference/headermap/set_from.md

set_from

headers:set_from(VALUE)

{{since('2025.10.06-5ec871ab')}}

Assign VALUE to the From header.

VALUE may be either a string or a MailboxList.

If you assign using a string, the string will be parsed and validated as being compatible with MailboxList before allowing the assigment to proceed.