Sendgrid integration with Plone 5.1

I cannot force Plone 5.1 to work with Sendgrid.

Sendgrid SMTP Relay configuration configuration looks like this:

The host has to be '', then I am not sure what about ESMTP. I used my Sendgrid apikey and the value of ESMTP as the login and the password. I tried all ports, nothing works :frowning:

It's not a firewall or network issue because I can send an email from the terminal. I tested Sendgrid Web API using Node. I have only a problem with SMTP Relay settings in Plone :frowning:

Hmm, the username has to be literally: "apikey". It started to work.