Do expired, revoked, self-signed S/MIME certificates trigger email SPAM filters or affect mail delivery?

For example, I have an expired or revoked S/MIME certificate. Can I sign or can the recipient encrypt a message with it? Will an email client allow it? If it is possible, will the message be rejected by SPAM filters? And what about the messages signed and encrypted by self-signed S/MIME certificates? Are they treated…

Postfix myhostname suggestion has trailing ‘.’ Where is the bug? In dhclient, postfix or where?

After a minimal debian stretch installation using (debian-9.8.0-amd64-netinst.iso), where hostname is left at the default debian and domain was left empty, installing postfix fails because the detected fully qualified hostname contains a trailing . character. I think it is dhclient that saves the resolv.conf file on a minimal install without Network Manager. It has trailing…

Cloud Shell has been disabled due to a Terms of Service violation

I just started using the GCP for learning cloud technologies and literally the second day I got this error: user@PC:~$ gcloud alpha cloud-shell ssh Starting your Cloud Shell machine… ERROR: (gcloud.alpha.cloud-shell.ssh) PERMISSION_DENIED: Cloud Shell has been disabled due to a Terms of Service violation – ‘@type’: type.googleapis.com/google.cloud.shell.v1alpha1.CloudShellErrorDetails code: CLOUD_SHELL_DISABLED Is there a way to learn…