It will no longer be possible to use Legacy Authentication in Microsoft 365 after May 1st. This will primarily affect older protocols like SMPT, POP3 IMAP and MAP. The reason is that this type of authentication is considered insecure, almost all password attacks are targeting these services.

Most likely, this will have no affect on you, but if you use an older email client, there are guides on https://www.hb.se/en/staff/for-my-work/it-services/e-mail/outlook/ on how to use Outlook on your computer or add an email account on your phone.