Email works using phpmail function, which is awful for email delivery. We insist in that you should use a SMTP transactional service to send your emails.
I copies and pasted the settings directly from the email.
port 25 does nothing
changing it to port 465 crashes the whole system
Then it says my SMTP server and username is invalid.
My SMTP server and username is valid.
And I was faced with the fact that SMTP does not work. It turned out that the Scaleway had SMTP disabled by default. The solution is to enable the VPS in the settings. Be aware of this possible fact.
U have to setup your own mail server, or u can use already the implemented one by your hosting provider, if u have one, if not, u have to setup at your own a SMTP server, and this is not part of Chevereto software.