[Feature Request] Add Native SMTP/IMAP Support for Outbound and Inbound Email

[Catmily]

Hiya,

Currently, FreeITSM has excellent, robust integrations for enterprise cloud environments via Microsoft Graph API and Gmail API OAuth2 tokens. However, the platform lacks support for standard, legacy SMTP and IMAP protocols.

For deployments running in completely air-gapped systems, localized corporate networks, or utilizing independent email providers (e.g., SMTP2Go, self-hosted, or local relays), it is impossible to hook up ticket ingestion or automated email responses. This creates a hard blocker for organizations like ours outside the Microsoft/Google ecosystems.

Describe the solution you'd like

I would love to see a simple "Fallback" or "Generic Mail Server" option added alongside the existing Google and Microsoft configurations in the Mailbox settings.

Implementing standard, password-authenticated (or App Password) configuration fields would bridge this gap:

• Outbound (SMTP): Fields for Host, Port (25, 465, 587), Encryption type (TLS/SSL), Username, and Password.
• Inbound (IMAP/POP3): Fields for Host, Port (993), Username, Password, and Target Folder for incoming ticket creation parsing.

Since FreeITSM is elegantly built on vanilla PHP, libraries like PHPMailer (for SMTP) or standard PHP IMAP extensions could be integrated with minimal overhead to act as the processing engine when the user switches the connection type away from OAuth.