The programme won't let me set up the SMTP for one of my IMAP accounts. Why?

1

Account details:
incoming mail server: mail.kein.org
ssl port: 993
authentication: password

outgoing mail server: mail.kein.org
ssl port: 587
authentication: password

2

Change the security policy to “Use SSL/TLS on special port (Legacy)” and let me know if it helps.