my outgoing emails are to gmail.com, so that may imply that the Smptmail emacs package is being used, and given there were changes to starttls, could there now be a mismatch in there somewhere?
my outgoing emails are to gmail.com, so that may imply that the Smptmail emacs package is being used, and given there were changes to starttls, could there now be a mismatch in there somewhere?