My apple email continually displays a message " invalid security certificate" and blocks emails. Please advice as to correct security certificate?
Simple suggestion first: Do you have the date and time on your Mac set for 'automatic'? If you have them set manually, it can cause some weird issues like this, especially if the system clock starts to slow down.
Second, do you have an option to tell your Mac Mail to accept the Shaw certificate? If it's been blocked once, it might just need to be accepted this time.
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