Unable to setup SMTP in mattermost

NethServer Version: latest
I have been trying for a week now to setup SMTP to enable sending emails in mattermost, but have not been successful Has anyone had luck with the process.
i keep getting error when i try to test.
ALl the details i have set are correct as i have used them in other system and they work fine

Did you check into log on the mattermost side (and on the SMTP side) if there’s more specific than “error”?
Do the passoword contains special characters as " or , or ' ?