Using the New Outlook for Mac features in business environments
(Partial copy of response to Patricia Daniel in this thread)
I did check with Best Buy's Geeksquad (where I bought my laptop) and they mentioned that anyone with a IMAP type email account used by Roadrunner on Spectrum (uses .rr in the email address) is no longer compatible with Outlook. The change was recent and the Geeksquad tech noted that they have had a number of recent cases of Outlook users with Roadrunner email accounts reporting receiving and sending email problems. The solution was to switch to using Spectrum Webmail (which isn't as good) but I can get emails on my laptop again.