[feat]: Enable email notifications

[elvece]

Option 1 (Start9 email)

• select to receive emails from Start9
• enter email address
• enter verification code

Option 2 (SMTP)

• select to receive emails from SMTP server
• enter credentials in form
• send test email

[MattDHill]

Due to email being a centralized pile a shit, instead of sending email from an SMTP on EOS, users can insert external SMTP credentials (SES, Mailgun, etc) in EOS settings, and Embassy will use that.

[elvece]

Add option to subscribe to start9 email delivery

[adamj7]

Enable Notification options: [On Success, On Failure] as checkboxes so that both can be selected to enable an "always" notify option Summary/Detail (that would include some sort of log file of detail)

Enable Notification Method:

1. Start9 Delivery
2. Custom SMTP a) Mail Server b) Mail Server Port c) SSL/TLS Checkbox d) Email From e) Email To f) Subject Line (Allow variables like Device Name) g) Enable Authentication (BASIC Auth, MS Graph API Integration, OAuth2)

Enable Output Options - TXT based email, HTML based email, PDF Attachment with 1 of the 2 prior methods.

Email Delivery when using the SMTP server of the recipient Mailbox is local (on the same box) is private and never leaves the server. When coupled with SSL, there is a high level of privacy. O365 and Gmail have ways to send unauthenticated email (when using a custom domain name) so long as the recipient address is at the same domain.