Normally I think you would / should know what messages to expect, eg. those that relate to the purpose of your process. In this specific case, you could most often easily pattern-match any other messages you expect first, then pick it off and check if it’s a Mint message as the final case.
The problem with selective receive is that it can have a performance penalty if your mailbox has a lot of messages in it; also, you usually want a catch-all case somewhere in your main process loop to avoid message overflow.
For more in-depth info, see eg. Elixir Messaging - How To Optimise Performance which is a good overview.
