On Fri, Mar 25, 2022 at 06:01:43AM -0400, Michael Grant wrote: > > Unless there's an existing function in some plugin to do this, I'll > have to write my own. Little surprising that there isn't, this seems > like an obvious check!
There is already very basic HEADER() template support added in trunk/4.0.0, this would generally work: askdns UNSUB_NXDOMAIN _HEADER(List-Unsubscribe:host)_ MX [NXDOMAIN] It just tries to find something resembling a hostname (having valid TLD) in the header, preferring to match @(.*) first. So it doesn't differentiate between http, mailto etc.
