As another user pointed out - I use the separate email addresses for separate side projects. Some have additional team members on the domain, some have just me.
I used to try and run them all under one email client, but it got messy to try and keep replies separate and coming from the correct domain address (for support and marketing queries etc.). Also, trying to run one inbox on mobile was achievable, but tricky.
I like having each web app domain in a totally separate, sandboxed inbox. Occasionally I delegate the handling of a particular inbox to another team member for a week or two while I am either away or working on a project, so it is nice to be able to attach/detach an Inbox from my conscious management whenever I like.
In order to redirect, you still need smtp server for the domain. Also if these are for some side ventures, handling correspondence via single inbox can be bit inconvenient and error-prone.
