I am using Mail App, People App and Calendar App on my Microsoft Windows Home Edition 20H2 OS.
In Mail I have 3 accounts: an Outlook.com account, an iCloud.com account and a local provider account: Telenet.be
all works fine in Mail App but in People App and Calendar App when I open settings (gear icon) I only see 2 accounts (Outlook.com and iCloud.com); adding a third account leads to error: 0x80004005
Can anyone help me with that problem please?

another additional question: in the settings of my telenet.be account I see (automatically added with the creation of the mail account)
for incoming email server: imap.telenet.be:993:1
for outgoing email server: smtp.telenet.be:587:0

I think the numbers 993 an 587 are port numbers but I have no idea (nor can't find) what the numbers 1 and 0 mean.
Has someone an explanation please?

thanks in advance, gabriël