I am on OpenBSD 7.5-current playing around a bit and noticed that smtpd fails to start.
I then ran smtpd -d and I get: credentials[40067]: warn: table-api: imsg_get: Result too large lookup: table-proc: no services registered smtpd: process lka socket closed
Probably the beginning of API changes: https://www.mail-archive.com/misc@opensmtpd.org/msg06266.html
