Error, when e-mailing invoices

[Patch]

Have a look at

For sending emails, custom SMTP now required

In previous versions, Manager could send emails without setup. This no longer works. Background Email protocol is abused by spammers who send unsolicited emails and as a result, email providers are employing various anti-spam detection mechanisms to be able to tell legitimate emails from spam emails apart. In order to make sure that emails sent from Manager are not considered as spam, we’ve been using reputable SMTP relay service from Mailgun.com Unfortunately Mailgun.com has shut down our a…

and Forum smtp category
https://forum.manager.io/c/smtp