imap.sfu.ca can not be verified message in iphone

"imap.sfu.ca can not be verified message" message popups in iPhone,
Remove those accounts using imap.sfu.ca, add accounts using mail.sfu.ca instead.
To remove email accounts in iphone 8.
1) Go to settings
2) Passwords & accounts
3) Click those accounts using imap.sfu.ca
4) Click "Delete Accounts"

To add accounts using mail.sfu.ca:
https://www.sfu.ca/sfumail/using-sfu-mail/getting-started/mobile-devices/ios.html