From my understanding the message originally tried to fool the user into clicking some seemingly expected link (as shown in the text) which in reality is a different link (href attribute in the actual link), i.e. something like
This trick was successfully neutralized by some secure mail gateway ...
No, it's not possible. It would be difficult to implement securely, and also pointless because of all the ways to get around it. What if Alice saves the email externally? Or screenshots it? Or uses an email client that doesn't support macros? If something is displayed on someone else's screen, there's usually nothing you can do to prevent them keeping a copy ...
Short answer: no.
Longer answer: If your PGP encryption is vulnerable to known-plaintext attacks, then that means PGP is using an old broken cipher. Modern, non-broken crypto (with updated software) will not have vulnerabilities like this. You can encrypt or sign whatever you want and no secret key information will be revealed.
Delivery from the MUA is usually done to the domain specific mail provider (MSA in your image). This communication is typically done either inside a companies protected network or to some external mail provider. Mail delivery inside the local network is usually protected against DNS spoofing as long as it can be assumed that there is no attacker inside the ...
This is a common phishing scam. It is meant to work like this:
Mallory is a baddie and figures out that Alice knows Bob. (Lots of ways this can be done, classic examples are looking on LinkedIn or reading employee lists published on the web.) Often Bob is Alice's grandboss or similar.
Mallory sends a mail to Alice, using a free email account with something ...
The short answer is no.
That error means that there is a problem on Openmailbox's end of things and changing how you connect to it will not resolve the problem on their server. You should contact their support, and let them know their SSL is not validating properly, then wait until they fix it before trying to connect to your inbox again.
Generally there are multiple Ways to forward E-Mails:
Users can create a forwarding rule within Outlook or Outlook Web App
An administrator can create a client rule for forwarding
An administrator can set the ForwardingSMTPAddress parameter on a mailbox
Users can set the ForwardingSMTPAddress parameter on a mailbox
An administrator can set the ...