Configuring modules for email sending and formatting is a pain and confusing. Most mailing modules rely on Mailsystem module to help configure this.
In D7 Mailsystem 3.x there's an improved method of doing this by using a delegator class. https://www.drupal.org/project/mailsystem/issues/1508104. I propose that the class and related functions be put into core. The UI can stay out of core.
This will help any combo of modules share the responsibility of sending emails. One module can be used for formatting HTML (MimeMail, HTMLmail) and another for sending (SMTP, PHPMailer, Postmark, SendGrid, ...). The popular modules can then use the new class to allow other modules to share in the work and also provide a simple UI (without needing to install Mailsystem if they don't need that extra power).
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@yorkshirepudding thank you for the additional info on improving discoverability and a handy way to keep a list of projects for reuse.
Why not add a Github star?
It is a good point @izmeez and when I was researching repo discoverability I found that GitHub search does prioritise matches with more stars. This is what I was researching for:...
Why not add a Github star?
Do you have a separate development environment and transfer database and config between sites?
Wierd happenings regarding updates...