Credentials configuration for email
| actor | object: |
| name | display name to use when sending email |
| address | sender address when sending email |
| object | object: |
| objectType | always ‘credentials’ |
| imap | object: |
| host | the imap server to connect to (string) |
| port | the imap port to connect to (number) |
| tls | whether to use tls (boolean) |
| usename | imap username (string) |
| password | imap password (string) |
| smtp | object: |
| host | the smtp server to connect to (string) |
| port | the smtp port to connect to (number) |
| tls | whether to use tls (boolean) |
| usename | smtp username (string) |
| password | smtp password (string) |