It seems that it is Microsoft is deliberately causing the 'bouncing' of a percentage of emails if using Microsoft Outlook under SMTP - all other email clients are currently unaffected. It is a security restriction that they have created to get Windows TLS email security pushed to a later version (TLS 1.2). Note that this ONLY affects the use of SMTP button and not the Outlook one.

"Exchange Online will begin rejecting a small (unspecified) percentage of attempts to make SMTP connections using TLS 1.0 or 1.1 and issue this error message -

421 4.7.66 TLS 1.0 and 1.1 are not supported. Please upgrade/update your client to support TLS 1.2. Visit https://aka.ms/smtp_auth_tls

This is a temporary error and clients can retry the connection. Exchange Online will block only a small percentage of connections it?s likely that the next attempt to connect will succeed. However, that small percentage of declined connections will increase over time to gradually make it more painful for clients using the older protocols to connect to Exchange Online. As Exchange Online declines more connections, clients will experience delays in transmitting email. In some cases, depending on the client?s error handling, email might not get through until someone updates the client to handle frequent retries (or upgrade the client to TLS 1.2."

The source code of the sent emails from Sameday Express indicate that they have ALL been sent under TLS 1.2

Until this annoying situation is resolved we suggest using ?relaying? to get around the issue.

We opened up a Google gmail account then linked our email address to it. We then used the gmail SMTP server settings instead of Outlook and not a single email ?bounced?.

Other relaying systems should work as well, such as smtp2go.

See our PDF on how to use gmail in Downloads on our web site - Outlook_SMTP_TLS_1_2.pdf

Norman
 

You may get this on iPad, iPhone or Android.

Solution - Delete your current wifi connection and then recreate it.

Norman
 

The root certificate that Let's Encrypt use for the certification path recently expired, meaning that security certificates that were issued using this are now displaying security warnings.

The answer is to force the renewal of the site certificate manually to use the new root certificate.

In a Linux terminal Window type -

certbot certificates

This will show the sites connected with the certificate.

Then try -

sudo certbot renew --force-renewal

or if you have one site -

sudo certbot certonly --force-renew --cert-name sitename.com

or more than one site -

sudo certbot certonly --force-renew -d sitename1.com -d sitename2.com

This should fix the issue.

Norman
 

free -h checks memory
df -h checks disk space
ifconfig shows network setup
cat /proc/device-tree/model gives Pi model number
sudo hostnamectl set-hostname newname sets hostname

Norman
 

"Application has failed to start because its side-by-side configuration is incorrect".

This has loomed up following a recent Windows update.

If you download a program from the internet then try to install it then you get a message similar to the above. It does not install anything.

It seems to be caused by a faulty Microsoft Visual C++ redistributable package. The quickest 'cure' is to go into Control Panel then Programs and Features then REMOVE ALL Microsoft Visual C++ redistributable packages.

Then - reinstall them all. I found a single source here - https://www.techpowerup.com/download/visual-c-redistributable-runtime-package-all-in-one/

Norman