Multiple AND and OR operator structures in segments


This is a big disadvantage of MW - the inability to choose multiple AND and OR operators

IF (a OR b OR c) AND d


And many more other combinations
That's a keen observation, indeed.
In latest releases, we have improved segmentation speed, so we're very aware there's room for improvements here.
Adding ability to combine conditions is something we'd like to add, its just so far, we haven't found a way to do it properly and maintain performance, and TBH, as it stands right now, I don't think things will change in MailWizz 2.x, maybe in 3.x where we'd be able to rewrite the way we handle segments entirely.