I have built an AutoMod bot for my instance, lemmy.basedcount.com. The bot covers the following features:
Automated removal
of posts, based on their title, content or link
of comments, based on their content
configurable with either regular expressions or substrings
User whitelisting and exceptions for moderators to selectively lift some or all of the aforementioned rules for certain users.
Mention based pinning and locking of a post, through commands exclusively available to the mod team
Discord notifications for new registration applications through a webhook. [only for admins]
Naturally, the bot is completely open source. I have also written a rather comprehensive (albeit long-winded) documentation and some examples.
This project is mainly targeted towards admins of small instances, however anyone can spin up their own AutoMod instance for their favourite community (provided they are a moderator there).
The automoderator is also available as a Docker image, for ease of installation.
Feel free to suggest any additional features that you might want to see added to this bot.
Yes! When setting a removal rule for a post or a comment, you can fill an optional message field. After having removed the content, the bot will reply to the user with whatever you have written there.
It's a big problem in how Lemmy handles removals. I currently have to send a PM to each person explaining why and where they can post instead (e.g., asking them to post tech support questions to !askandroid@lemdro.id instead of !android@lemdro.id).
Thankfully Photon makes it easier to do this in one step, but it doesn't support managing multiple types of responses.