Using Outlook for Android in business environments for email and scheduling
Same/similar problem on Galaxy S8. Email is myname At mydomain dot co dot uk *** Email address is removed for privacy *** hosted in UK by Plus.Net. Worked for 2+ years till end of August using IMAP settings to access IMAP and SMTP server. No changes by ISP so now have to use Android Gmail to access my emails on this account. Disappointing Microsoft!