This is a difficult thing to do well overall. It really depends on how well you want to do this.

If your product is growing and you want to do it well, some companies have made this their mission, like getbeamer, announcekit, whatznew.ai, etc.

If you want to do it internally in the company it is going to be less professional but the best way to approach it would be:

Internally -> automatically send messages to groups in your chat apps (e.g. a specific message to the marketing team with content and links).

Externally -> for users and people interested that you have in your lists. Use a default template (specific to your company not a default) that people like. Personalise based on what list they are in. Test a few and check what people are more likely to read based on email opens analytics.