Can't add SMTP-server to Gmail

I'm hosting my domain at DigitalOcean but you are handling my e-mail needs. However, I can't add the SMTP-server so that I can send from Gmail the error I get is:

"535 Authentication Failed code(535) "

I've created an app-specific password (now disabled 2FA).

The SMTP-servers I've tried is smtp.zoho.eu and smtp.zoho.com tried both

info@mtbnyheter.se and eriohm@zoho.com as usernames, tried both SSL and TLS.

MX Records, SPF and DKIM all have green check marks in the control panel.

Nothing works. Why not?

Also tried to add my e-mail to Outlook. The IMAP authentication works fine, but again the "login" to the SMTP-server is failing.

Please help! :)

Sincerely,
Erik Ö