Caution sign flashes when opening Office Outlook from task bar. - Microsoft Community

morning when opening office 2016 outlook outlook icon in task bar yellow triangle , exclamation mark flashed few times whilst outlook opened. there doesn't seem problem outlook not sure caution trying tell me. have not seen before today. have 3 email addresses in outlook 2 use imap , outlook.com address uses microsoft exchange. thoughts please?

if see caution sign (yellow triangle exclamation point) on outlook icon, means program not authenticating exchange server , have possibly lost connection.  check on couple of things:

1. check have network or internet connection.
2. if are, may need check outlook settings ensure authentication setup has not cleared itself. may involve putting user , password.

recommend send test email check if gets sent , received recipient.

should need more help, let know.

Office / Outlook / Windows 10 / Office 2016