Attached is a patch to fix the build by regenerating the certificates. Note that a Makefile to update the certificates was introduced in the version that updated the certificates. In those versions we can simplify the before-check hook to be:

(with-directory "test/net/fixtures"

  (invoke "make" "regen_certificates"))

Another question, we are packaging a ~2 year old version. When updating the version, should we drop the before-check lambda? Or should we keep it in case someone wants to build ruby-net-smtp in the year 2034?

Cheers