I cannot get my IMAP email to work in the outlook app on my new S7 Edge,

[AC Question]

I had to change from one Samsung S7 Edge to a newone due to a broken screen, I set up my emails as before (2 yahoo and one IMAP) - they all worked for a day and then the IMAP account stopped working and I have removed and tried to re- add it but then get the different messages, ranging from verification of password to no server response, to the certificate of the server not being valid. the IMAP email works on my laptop, and on an iphone
any suggestions?
thanks