How to bypass Mailpit in DDEV?

Problem/Motivation

I want to be able to test Postmark in DDEV, and allow emails to get sent to Postmark, and not get intercepted by Mailpit.

It is possible to override a SMTP set up in DDEV, but how can you do it for a non-SMTP mail service, such as Postmark? Sending email with [Postmark] API.

See also the DDEV Github issue.

Steps to reproduce

Proposed resolution

Remaining tasks

User interface changes

API changes

Data model changes